This story sounds a lot like mine. I started "publishing" when I was 15. My parents started studying with the witnesses when I was 9. My mom was very critical, called me a fanatic, said she noticed that the CO got special treatment, sarcastically called me "the preacher" when I did anything she didn't like, and so on.
I quit the dubs when I was 32. A few years later, my mom got baptized and became a "true believer." I think it was because she had failing health and "couldn't" do all of the Jw stuff. She listened to the meetings by phone and did not go out in service. When my daughter pointed out some doctrinal inconsistencies, she said, "I would talk to them about it, but they'd take it the wrong way." When I was not around, apparently she sorrowfully would tell other family members (none of them dubs), "My oldest daughter used to be such a gooood little Jehovah's Witness."
Who could ever know what she was really thinking? Not I.