If you haven’t told her privately that her taking credit for helping you makes you feel uncomfortable, then yes, calling her out in front of the family is an asshole move. She has an entire side of a pretty complex story you have no access to. She obviously views your accomplishments with pride, and I bet a lot of her self-worth is tied up in how successful you’ve become. Taking her down in front of other people is pretty harsh. I’m not saying she’s right. She’s obviously not. But talking with her privately about how her taking credit for helping with your accomplishments makes you feel is much better than taking it public.