My boyfriends mom....

I’ve been with this guy for a year. His mother has never made me think she dislikes me. But when she’s not in a Good mood she makes remarks or is a bit rude. She also isn’t very pleased with my personal style. Made a remark about a spiked choker I wore. Recently i made a joke because she was trying to get my boyfriend to not eat her pie. So i said lemon meringue pie taste is just egg pie (because he has a sweet tooth I assumed it wouldn’t catch his interest) but she took it as because I’m vegan I was implying he was suddenly not allowed to eat eggs. And asked him “oh are you NOT ALLOWED to eat eggs anymore?” I explained my joke. But she’s very unapologetic most of the time. I’m not sure if she really doesn’t like me or has issues with those parts of me. I really want things to work with him. How can I help better the relationship with his mom? I’m not a bad person. Her son and I never argue or fight. I’ve never been disrespectful to him or his family.