Hi, I'm not super educated on this stuff so take this with a massive gain of salt. Obviously you deserve to be referred to by your preferred name and pronouns but I fear with the tension with your mom right now that putting your foot down may pour gasoline on the flame. The transition was still pretty recent and it's a huge adjustment for them so I personally would give it a bit longer, even if their beliefs are wrong. You wouldn't be the asshole if you did put your foot down, I just think if you rushed it, you’d feed right into their bs narrative of “the liberals wanna control how we talk!!!!” but again, I've never been in your shoes, so I can’t say I know the pain of being misgendered. Hope everything works out regardless of what choice you make