Transgender family member

I'm at a loss. My brother is transgender so... my sister. I accept it, though I'm still trying to understand it. I'm still wrapping my head around it. Anyway my parents do not accept it. They say they do but it's obvious they don't. My relationship with my parents has become awkward and we barely speak because they don't like that I'm on my sisters side. I'm stressed out because I'm going home for Christmas and I know they will pull me aside and start nagging me about my sister and her "choices". Honestly I'm tired of hearin about it. It's not my parents business anyway and I'm tired of being in the middle of things. I'm tired of my parents being idiots about this. What should I do?