Joy Simonson didn't expect to stay around long as executive director of the National Advisory Council on Women's Educational Programs after the Reagan administration installed new members. But she said she was surprised that the new council's first order of business Monday morning was to fire her.

And waiting in the wings, "even before the body was cooling," as Simonson put it, were applicants for her $57,500-a-year job. The winner was Rosemary R. Thomson, a Reagan election-campaign worker and Illinois state director of Phyllis Schafly's Eagle Forum. She had filled out an application for the job July 6, nearly two weeks before it became available.

The administration and conservative groups have targeted the $6 million-a-year Women's Educational Equity Act (WEAA) program for extinction, but Congress has continued to appropriate funds. A Conservative Digest magazine article earlier this year on "defunding the Left" focused on the program and attacked grants it had made to feminist groups. The director, Leslie Wolfe, was transferred to another position after the article ran.

The 20-member advisory council makes policy recommendations to the program officials and reports to Congress on progress in women's education.

Thomson said in a telephone interview from her home outside Peoria yesterday that she had applied for the advisory council job after getting a call from an Education Department official "suggesting there may be a vacancy." She said she was a little surprised herself that she was hired so fast.

In her application, Thomson said she was a substitute schoolteacher in Morton, Ill. In an attachment covering her political experience, she said, "My suggestion for a huge banner 'Reagan Plays Well in Peoria,' captured the attention of the national media and was used again for the final campaign media event in Peoria the day before the Nov. 4th election."

Her volunteer work also has included being state director of the Eagle Forum since 1975 and publicity chairman for the local Chamber of Commerce's annual fund-raiser, the Morton Pumpkin Festival.

Thomson said in the interview that she recently helped review applications for WEEA grants and testified in Congress against what she called "excesses" in awarding funds. Citing a $95,000 grant to a Berkeley, Calif., studio that made three half-hour films on how teenage boys could become babysitters and housekeepers, she said:

"That doesn't benefit education. That benefits a film maker. We don't need things like this at a time when people are begging for jobs and going hungry."

She said she opposes the Equal Rights Amendment and sees her new job as examining the program "and trying to get the most out of the taxpayer's money."

Simonson said she was disappointed at what appeared to be the orchestration of her dismissal. New council members read prepared amendments to the rules adding personnel matters to the agenda and deleting notices and appeals of terminations, she said.

"Previous councils have prided themselves on their independence and bipartisanship," she said. "I regret that it appears this council lacks independence."

Some women's and education groups already are protesting the firing.

Barbara A. Stein, chair of the National Coalition for Women and Girls in Education, wrote White House women's adviser Wendy Borcherdt yesterday that the abrupt firing of Simonson "is one more demonstration of the administration's lack of concern for the women of this nation."

Willard McGuire, president of the National Education Association, issued a statement saying that the quick action against Simonson "demonstrates this firing was organized and orchestrated by the administration."