"One distressing thing is the way men react to women who assert their equality: their ultimate weapon is to call them unfeminine. They think she is anti-male; they even whisper that she's probably a lesbian."
Shirley Chisholm was a Democratic State Legislator, then a Member of Congress, and ran in the 1972 Democratic Primary for President.
Despite this it seems possible that she might have been a feminist. As she opposed the Vietnam War, stood for full employment, and fought for the Equal Rights Amendment and legal abortion, I can't find any holes so far.
Conclusion: It seems unlikely that you could be a feminist and a member of Congress, but it may be possible.