AITA for refusing to call my niece by her new name?

I have a niece who is 22 years old. Her parents, my sister and brother in law, named her after the Disney princess. <br><br>Anyway, she went away to college, came back, and said she wanted her name to be changed to something else, like Jane. She said she hated her name and she wants to distance herself from her family. <br><br>Ok, weird. Whatever. My sister was pretty upset about it, and my brother in law was just like “oh you get used to anything”, so his attitude is whatever, just don’t break the law.<br><br>So my niece moves to a new state and she goes by Jane there. But when she comes home to visit, she insists everyone call her Jane, not _________. She got mad when my mom said anything. We’ve argued about this before but we always dropped it. <br><br>This year, thanksgiving dinner was at my house. We all sat down and my niece said “don’t forget to call me Jane tonight”. I said that’s not happening and she got mad and said we were invalidating her. I said she’s not “Jane” to me, she’s my niece _________, and my mom said yeah, you will always be _________ to us. <br><br>She called me a BITCH later and said I have no respect. I just think why would I call her something else when she’s my niece _________? But she says that I have no respect and that I’m the asshole. AITA?