My story is a little different. Having grown up with an extremely feminist mother in the 50's who broke down barriers in my home country, and was quite famous as being probably the first divorced, single mother BY CHOICE (she left my father for not wanting her to work outside the home), I took my liberties and freedoms for granted, and actually rebelled against feminism in the 70's and 80's because the message back then was that babies are somehow blah-blah and only for stupid brain-dead women and you had to go to work and be like a man. I felt that feminism was taking over male values unquestioningly and I felt that were wrong. I wanted a society that honoured what we were as women, mothers, grandmothers, as I felt our contribution was every bit as vital as males, even if we spent years at home rearing our children, teaching them to be good humans. I felt we were better at this, in a different way, than men, and that it is essential work, just as essential as earning big money or having a top flight career.
Perhaps in a rebellion against my mother I was determined from the start to be a SAHM, and fought against the feminist idea at the time that you'd just be a boring old dogsbody if you did that. As OP says:
Yes totally this! The narrative is very much get back to work ASAP so you can do some proper work that actually matters to society. I found motherhood so hard and all consuming and just wanted to be with my baby most of that first year but I was constantly asked when I was going back to work and people said things like you don't want to be just a mum. I felt that somehow I was letting the side down. It made me see how the work of caring (typically women's is so looked down on by society).
I had my first child when I was 35. I was a single mother working part-time at first, but by the time my daughter came along five years later I was in a position to stay home with her. I had to constantly put up with remarks about my "brain getting rusty" or "going crazy at home" or "not doing real constructive work". I assumed that was feminism of the day and I rejected it. I was confident about being a SAHM and did not see myself as lesser in any way.
So I rejected the label "feminist" for decades, though at one stage I did try to be one (before I had children). In the late 70's I had a subscription to Gloria Steinem's monthly magazine Ms. But that too went more and more in the direction of rejecting any kind of hands-on motherhood. At one point Ms was discontinued, and instead they sent me the new title: "Working Woman", without asking. I cancelled my subscription immediately.
I did my thing and don't regret it in the least.
What made me a feminist in this day and age, and even reconciled me to the label, is Transideology and this forum. Yes, it was MN that radicalised me. I have two, soon to be three, granddaughters (no GS's) and I need to help clear the way for them.