Tough question... my Mom was sort of the same way. If you can tell her and at same time convince her that it's not a negative thing then go for it. If you can't I'd say to keep it from her. Not only is it not worth the hassle - but you don't want to hurt her either. I know it might feel good to get off your chest but not at the price of hurting her or changing the way she thinks of you. It's cool if a stranger or a friend doesn't agree with me or my lifestyle, fuck em... but family is a different story. It doesn't matter how hard to try to explain your point... some people just wont understand. If you don't think your mom will understand maybe it's best not to tell her.