The Indians aren't even sure what to call her. They've come up with "first lady," although they aren't happy with that because it sounds so American. Their difficulty is understandable. For the first time in the Nehru dynasty that has dominated India since independence 38 years ago, the prime minister now has a spouse.

Jawaharlal Nehru was widowed, as was his daughter Indira Gandhi. But her son Rajiv has taken office not only married, but married to a 38-year-old Italian Catholic he met in a Greek restaurant while studying at Cambridge. Born Sonia Maino to solid middle-class parents in Turin, Sonia Gandhi is now most often simply referred to as Sonia -- a very traditional wife who is also considered one of the most powerful people in India.

Today she arrives in Washington with her husband on an official state visit, an elegant and striking woman who carries her sari so well that she has impressed even the Indian women, normally tough critics of any westerner who tries to wear a garment that takes a special walk and a lot of practice.

Sonia Gandhi speaks fluent Hindi as well, and the talk in New Delhi is that she is even better at it than her husband. For years, since her marriage to Rajiv in 1968, she expertly ran her mother-in-law's household at 1 Safdarjung Rd., the supreme housekeeper who oversaw the kitchen, the large staff and her own son and daughter, Rahul and Priyanka.

Like any convert to a cause, she is in many ways a more devoted Indian wife than the real thing might be, the obedient, loving daughter-in-law who was intensely close and loyal to Indira Gandhi, "Mummy," in her words, and who isn't afraid to say, as she did recently in an interview with Dharmayug, a Hindi-language weekly magazine, that "my upbringing is such that I feel my husband is superior to me and his mother even more superior."

It was Sonia Gandhi who rushed out on the lawn after Indira Gandhi had been shot on the morning of Oct. 31 last year, and who cradled her bleeding mother-in-law in her lap in the back seat of the car as it sped to the hospital. Rajiv Gandhi was in West Bengal and heard of the assassination over the BBC. Sonia sobbed uncontrollably outside Indira Gandhi's operating room, then later kept an all-night vigil by the body as it lay in state. In contrast, Rajiv felt it was important to keep his emotions under control. He later said he was annoyed by a story going around that "When I heard the news I went into the loo and had a bawl, that's all rubbish."

Seven months later, for all her presumed new power, Sonia Gandhi has yet to make a significant impact. She is only seen in public for the occasional large dinner or political event she decides to attend with her husband. Her first and only interview as the prime minister's wife was with the Dharmayug weekly, and she has turned down all other requests. Friends say she never wanted her husband to enter politics, and has not yet come to terms with her new life. Aides to the prime minister are quietly rolling their eyes, understanding her reticence but saying privately that at some point she has to learn how to be the first lady. For this article, she agreed to answer some written questions submitted through the prime minister's press adviser, H.Y. Sharada Prasad.

"I am not interested in a role as first lady," she said through Prasad. "I do not really have much time. The children are at home and are still young, but whenever I can be with my husband I am with him at many of the public functions and a good number of the dinners. My husband's duty is to the country, and mine is to the family."

Although there is some grumbling from those who see Sonia Gandhi's attitude toward her role as a lost opportunity to make a difference, Indians in general don't crave the kind of public performance and personal information about the prime minister's wife as Americans do of Nancy Reagan. People are curious, and fashionable women in New Delhi know that Sonia buys her saris at Sona, a private showroom, but how much they cost and what style they are is not a matter of consuming public interest. Some women in New Delhi social circles will say that she has not yet acquired a personal style like her mother-in-law had, but for the most part, Sonia Gandhi is admired for a remarkable ability to adjust to a country that often poses difficulties for westerners.

"I am a person who easily makes adjustments, and the Italian feeling for the family has helped me," she said through Prasad. "Both my mother-in-law and Rajiv made it easy for me. I feel very Indian and am not conscious of being an Italian in India. I do not recollect even a single incident when I had any difficulty in making an adjustment. I was never pushed into doing things I did not want to do."

But in her interview with the Hindi weekly, she talked of how often she thought of Italy during her early years in India. "In the beginning I used to feel it a lot," she said. "But then I took a decision. I cannot keep both. And until I establish a deep root and until I identify fully with my family here, I decided to keep myself cut off from my parental home."

Now there is talk in the Indian press about Sonia's "Italian connection," or her family's ties to Snamprogetti, the Italian multinational firm that often wins Indian government contracts. Sonia has never commented.

Friends, none of whom want to be named, describe her as a serious, thoughtful and shy person who exerts a moral influence on a husband who pays close attention to her opinions. For this reason, Imprint, a respected Indian news and features magazine, named her the seventh most powerful person in India -- ahead of the president, Zail Singh, as well as K.K. Birla and J.R.D. Tata, two highly influential industrialists.

Still, she says she has little influence over her husband on specific policy matters. "I am interested in what happens, but I am not the sort of person who politically interferes," she said through Prasad. "My husband spends the whole day in politics. I make it a point not to discuss politics with him when he comes home."

Friends also speculate that Sonia Gandhi can't be happy living under the intense security that has surrounded her family since her mother-in-law's assassination. She and Rajiv have moved from the old prime minister's residence on Safdarjung to a fortress-like home on nearby Racecourse Road that is protected by a concrete outer wall, barbed wire and security guards with carbines and sten guns. The children have been taken out of school to study with a tutor at home, and Rajiv Gandhi usually wears a bulletproof vest in public. The only written question that Sonia did not respond to was one asking how she had been able to retain a normal life under the new security restrictions.

One way to look at Sonia is to see her as a striking contrast to her politically ambitious sister-in-law, Maneka Gandhi, the widow of Rajiv's younger brother, Sanjay, who was Indira Gandhi's choice to become heir to the family dynasty. After Sanjay's death in a plane crash in 1980, Maneka tried to become a political force in her own right. Mrs. Gandhi threw her out of the house, but Maneka didn't give up. She formed her own political party and last year ran for parliament in Rajiv's own district, losing badly.

Sonia has never thrived on the tumult and passions of Indian politics. After Indira Gandhi lost the election of 1977, Sonia is said to have panicked, ready to fly back home to Italy with her two children and her husband, at that time an apolitical airline pilot. Maneka was resentful that she and Sanjay were left alone to fight the Janata Party government. "When the rest of your family was packed and ready to go abroad," Maneka wrote in a letter to Indira Gandhi as reported by Asiaweek magazine in 1982, she and Sanjay "fought so bitterly for you in the Janata years."

Sonia met Rajiv while she was studying languages in Cambridge at a school that was separate from the university. "There was a Greek restaurant, the only place we could get Italian food," she said through Prasad. "All of us Italians and many others from other parts of Europe used to go there, and Rajiv and his friends also. Some of his group knew some of my group, and we met just like that."

She told the Hindi weekly that it was neither her husband's good looks nor name that attracted her. "I could find an inner beauty in him," she said. "He was somewhat different from others, deeper and wiser than his outward looks."

These days she busies herself with her children and her work in art restoration. In addition to English, Hindi and Italian, she speaks French and Spanish, as well as a bit of Russian. Before the new security restrictions, she used to go to Amethi, the district in Uttar Pradesh that Rajiv Gandhi still represents as a member of parliament, distributing medicine, blankets and food to the villagers. Asked what struck her most about India when she first arrived, she said through Prasad that it was the "cheerful people -- in spite of their circumstances."

She has recently read Nehru's autobiography and last year watched "The Jewel in the Crown," the highly popular public television series based on Paul Scott's novels about the British in India.

"I saw 'The Jewel in the Crown' on cassette along with Mummy," Sonia said through Prasad. "I thought it was a little long and drawn out, but what struck me was the negative attitude of the British toward Indians and how they moved in a world of their own."

Sonia also said through Prasad that "Mrs. Gandhi, in spite of being prime minister, was not at all formidable. She was normal as any other mother would have been -- and very understanding."

She first met Indira Gandhi while studying in Cambridge. She told the Hindi weekly that her future mother-in-law was sympathetic, recalling her own controversial marriage to Rajiv's father, Feroze Gandhi, a Parsi from a middle-class family. The Nehrus were Kashmiri Brahmins.

"Sonia, I am a mother," she recalled that Mrs. Gandhi told her. "You need not be afraid of me. I was also a girl like you in love with a boy from a different community and religion. I can understand your love. Have no worries."

(Religion doesn't appear to be a problem in the marriage. Rajiv Gandhi said in an interview with the weekly magazine Sunday that "I am not religious at all . . . but I do believe in truth and what I feel is right, and I put my trust in somebody, you can call him God, and it works." His wife, he said, "isn't a practicing Christian in the sense of someone who goes to church every Sunday. She didn't do that in Italy, she didn't do that in England.")

When Sonia was preparing to leave her first meeting with her future mother-in-law, Indira Gandhi beckoned to her, took out a needle and thread, asked her to turn around, then mended a loose hem on her dress.

"I was really touched," Sonia told the Hindi weekly. "Indeed, this was the first gift I received from Mummy."