I have that same conundrum - my mother was an early 70s feminist who always worked fulltime, which was unusual in the very middle-class expat society I grew up in. It was what she wanted to do and she was bloody well going to do it - and I was proud of her for that.
And she'd be probably be turning in her grave if she knew that 40 years later her daughter is home looking after the kids, doing bits and bobs of PT work, while the man goes out and earns the proper cash.
But ultimately what she was fighting for wasn't just her right to work, it was her right to have a choice. And now I have the right to have a choice, and to be treated with equal fairness regardless of those choices. That's how I reconcile my feminism with my SAHM status.