She is hardly the first woman to have bought the Brooklyn Bridge. But that does not keep the edge out of her voice.

"I believed him," she said, sipping a beer and shaking her head in disbelief. "He said his divorce was on the verge of being final. He kept making these promises." Another sip."Bitter? You might say so."

This is far more than a woman talking of a romance that turned rotten. It was a romance that produced a child.

The parents never married, however, because there was no divorce. So for five years, the mother, 27, has been a single parent in many senses.

Single in the sense of her marrital status, of course - a situation she expects will continue. And single in the sense of being socially isolated. A date or friend must understand that her daughter's sniffles come first. Many don't understand. "So most of my friends are other single parents," the woman said.

Yet, in another sense, being a single parent has proved to be positive. "My life is much more flexible than married people," she said. "And I may be a better parent than a married person, too."

But economics are another matter.

Almost $200 of the $650 the woman takes home each month goes for day care. Outside of a refrigerator and stove, the only appliance in the kitchen of her Silver Spring apartment is a toaster her parents gave her.

Voluntary surgery on her car is unthinkable; only when it quits entirely does the woman repair it. Meanwhile, she has not had a vacation in three years.

The father does not contribute to his child's support. He did when she was younger, but in re- cent years the money has stopped. So the mother is in a classic bind: To sure him would cost more in attorney's fees than she can afford and would probably force her to see him again, which she does not want. "So," she says, "I scrimp."

But scrimping is easier, she says, than the awkwardness that being a single, unmarried parent can produce.

"I generally tell the truth, and if people don't like it, that's too bad," she said. "But sometimes, to strangers, it's easier just to say I'm divorced."

She has told her daughter the truth, the woman said, and the daughter appears to accept and understand it. But the child does not understand why she connot see her father. "She still remembers him," the woman said. "It isn't easy."

Neither, at times, is coping with office mates.

The woman, an editor for an education publication, is lucky enough to have a boss who is a divorced, single parent. So he never complains when daughterly case of the chicken pox forces his employe to "call in sick."

But a coworker gave a speech one day in the ladies' room about how much she disdained "illegitimate mothers." She was apologetic when she was informed that her "divorced" colleague wasn't really divorce. Still, the air hangs heavy.

But not as heavy for this woman as her relationship with the baby's father.

She came to Washigton from Ohio to attend a local university. In her junior year, she chose a major. An assistant professor 10 years he senior was the logical choice, in her field, as academic adviser.

"I had a terrific crush on him," she said. "One thing led to another."

The woman became pregnant the summer after she graduated. She says she did not consider abortion because she assumed the father would soon marry her. By the time she deduced that he had no intention of leaving his wife, it was too late.

"I though about adoption, but this was my flesh and blood. I had never though too much about kids. I didn't think I liked kids. but i decided nobody else was going to raise her.

"I was very scared. I was afraid I wouldn't love my daughter. But a bond develops. You're Mommy whether you've got a ring on your finger or not."

The woman earned a master's degree three months after her daughter was born. She regards tht as some thing of a miracle. "I was incredibly depressed all the time," she recalls. "All I could think about was the baby's health."

The waman's relationship with the father flickered and faded several times when their daughter qas an infant. The break was slow, and came only after the woman saw a psychiatrist. The parents have not met or spoken tor two years.

The woman claims it's all behind her now. Kindergarten will enter the picture this fall ("So soon! I can hardly and happy and "seems very well adusted."

So does the mother. She says she has "energy and self-esteem now" - enough to attend a single parents' counseling group, to pursue profissional she is jaundiced about not men, perhaps permanenty . But not, for a change , about herself.

"I've made it so very far on my own," she said. "There's nothing wrong with making it on your own."