One evening this past June, Billie Garde had a leisurely dinner with a friend on Capitol Hill. They discussed the apartment she had found, her new job, the school she had selected for her two daughters. On the way out, she stopped at a telephone to call her former husband in Oklahoma to tell him on what flight she had booked the girl's trip to Washington.

The conversation changed her life. "He simply said, 'The girls are not coming. You will never see them again.' I didn't believe him," said Billie Garde. In the next few hours, she found out that her husband had obtained a motion to change their custody agreement. It questioned her professional stability, saying she had abandoned her household goods, had no permanent job, no residence and no telephone. In the next few weeks she would discover that her case was part of a trend of custody disputes that question whether working women can manage both a career and children. In August, after a five-day trial that bordered on soap-opera motif, a judge ruled that, at least temporarily, Larry Garde was a more qualified parent. Billie Garde intends to fight that decision.

Both Billie Garde and Larry Guarde express convincing love for their children, Tanya, 7 and Deanna, 5. Both believe their own home environments are better for the children. Their stories about each other's attention to parenting vary, but they both say their personal feelings are secondary to the welfare of the children.

"I just couldn't send them back," said Larry Garde, 29, a modular building contractor in Ponca City, Okla., recalling that same long-distance conversation. Larry Garde denies he said his wife would never see the children again. "She said she had a temporary job, but something better was coming along. She had a small apartment. Out of the last year, I had had the children all but a total of five to six months, all voluntary on her part.When she had them, from February to May, 12 different people had taken care of the kids . . . My children crave stability."

"I was angry, hurt and upset," 27-year-old Billie Garde said the other day, drumming her dark, long fingernails on the wallpaper of her living room in Wheaton. The brown eyes of the tall, large woman telegraphed on unrepentant anger. At times she cried. "Yet, in those early hours, I was not totally distraught. I still felt obviously there were some misunderstandings. Yet it was the first time I had felt my maternal animal instinct. I had to hold those girls."

For a time, the marriage of Billie Pirner of Appleton, Wis., and Larry Garde of Muskogee, Okla., seemed smooth. A quick courtship in the Air Force. Some adventure living overseas in Taiwan, where the first daughter was born. The first four years, said Billie Garde, looking across the room at a friend as she begins to describe her personal life, were enjoyable. "But the last three were very difficult, our values and life styles grew further and further apart. My husband had erratic periods of employment and he physically abused me," she said.

Her former husband describes the marriage as less than idyllic. "I was under mental stress. Early on she told me she didn't really want to get married. When the first child came along, I was told I had ruined her career," said Larry Garde. On the charge of physical abuse, he said, "About the same amount, she beat me. For a period of time, I weighted about 135 pounds, she weighed 220 and 245."

In defining her parental role, Billie Garde says she had done the traditional but she also taught her children about commitment, through community and jobs. "The children must understand work is part of life. And it's not bad to say I like my work," she said angrily. "So I don't think I should stand in the witness stand and say I don't like my work. I do."

In October of 1978, the Gardes split up. She says he moved out. He says he moved to Wisconsin to find a new job because she thought the family needed to be closer to her parents. Ten months later she filed for divorce, and he eventually received summer visitation rights.

The summer of 1979 he and the children lived with Billie Garde's parents in Appleton, Wis. At the end of the summer, Billie Garde decided to keep that arrangement so that she could teach high school full time, teach junior college two nights a week and work on her master's degree two nights a week.

In January of this year, about the same time she took a job as the second-in-charge at the local Census Bureau office in Muskogee, she retrieved the children and had them until her former husband's visitation began in June. tIn the spring, she decided to move to Washington. "I guess it was the history teacher in me. I thought the girls would benefit from Washington right at this time in their lives," said Billie Garde. She said she talked it over with her husband. "I asked him if he had a problem with my moving, he said he agreed and that it would be good for my career," said Garde. "In June, it was his visitation month, so I left the girls with him, came here, found a job as a clerk with the Veterans Administration, had sublet an apartment and had found a school. Every step of the way, I checked with my ex-husband."

He says he supported her plan. "I encouraged her to go to Washington to find a good job. She feels her life will mean nothng if she is not remembered in the history books. She is an ambitious woman, and I feel that's good," said Larry Garde.

In late June, Billie Garde was the only named source in a series of controversial newspaper articles detailing the alleged abuses of the former director of Muskogee's Census Bureau. She believes that influenced her former husband's action. The same week the articles were published, Larry Garde, according to his sworn deposition in the custody case, contacted her former boss. The same day of that meeting, Larry Garde obtained the custody motion.

In the deposition, Larry Garde says of the Census Bureau newspaper stories: "This is the reason I am fighting for the kids." Larry Garde, in a telephone interview last week, said he started thinking about custody last fall when he and the girls were living in Wisconsin. He also said he had obtained the court order the day before the meeting, and the meeting had no bearing on his action.

From June to August, Billie Garde used the legal route to regain custody of her daughters. At the trial in August, Larry Garde's testimony emphasized his former wife's concern for her career. Billie Garde's attorney questioned his financial status, job security.

"The substance of their testimony attempted to paint a picture of me as an overly ambitious career woman who never wanted children. There were questions about how many times had I baked the kids cookies," said Garde, her legs tucked under her brown tweed skirt. She had juggled her schedule, she said, like any other working mother, at times having friends pick up the children at school, taking the girls on her business trips or leaving them with their grandparents. "I never pawned them off on people."

In the end the judge awarded the two girls, pending a review in a year, to their father. They now live with him and his second wife in a mobile home. In her three-bedroom apartment in Wheaton, Billie Garde has decorated a room in white eyelet and white wicker for them.

Her plight has pushed her toward a solidarity with women, through a church and women's groups, a kinship she felt more politically than personally before. "I have started looking at more than my heartbreak. I have started formulating the issue, the right of women for economic independence and creative expression," she said.

Right now she covers her nervousness about that role with talk about the girls. One of her most difficult days was July 4, Tanya's seventh birthday. "I had arranged for us to go to the fireworks, everything," she explained. The weekend before the trial began, she and her lawyer kept the girls. "Tanya's biggest concern was that her father had told her I wouldn't let her see him again. She wanted to know about her room, her school. She told me her father kept telling her I was too busy, I wouldn't have time with her, I would put her with babysitters all the time," said Billie Garde.

Larry Garde remembers another conversation with Tanya. "She said to me, 'If I live with you, I will probably see more of Mommy,'" said Garde.

The first weeks after she returned to Washington, Garde was despondent, getting on the wrong buses, falling asleep on the Metro, happy that her clerical job kept her buried in data. She withdrew from people. "I thought once people found out the judge had given my children to my husband that they would say something was wrong with me," she explained. Her grandmother, 70, came from Appleton to care for her. m

Then she saw a newspaper clipping about a case in Iowa in which a law student, Linda Lou Tresnak, was denied custody of her children. She called her, they cried, they exchanged court papers, and Garde found a new kind of support. The same thing happened with Roberta Milovich, the Illinois woman whose case also seems to indicate a trend among the courts that working women may not be good mothers. Milovich has reached thousands of living rooms through Phil Donahue's show. Garde, too, has gotten her call from Donahue. "I am the only one who has had the children taken from me," said Garde.

Calvary Lutheran Church in Wheaton raised money for her air fare back and forth to Oklahoma, stocked her cupboard. The Women's Equity Action League Fund set up a fund, to which the public can donate funds for her legal expenses. "We usually help with employment or education discrimination cases, but this is more than just a custody case. This is a trend where the judges are saying, 'You will not be economically free, upwardly mobile. You will stay in your place, take a secondary job.' This attitude affects women down the line, with lower Social Security benefits, a total life pattern," said Maxine Forman of the Fund.

Billie Garde thinks she can endure the political fuss, the thrust into the limelight. In a way, she is enjoying it. But she keeps reminding everyone the children are her priority. "I want the issue to be the children. I just want my girls back," she said, slowly. "And right now my biggest fear is that they will forget me."