I feel your pain. I have ‘one of those’ for a sister, too! AND, as an added bonus, she’s gay! Happily, she’s not obnoxious about it; has had the same ‘partner’ for 18 years - who I actually like a lot.
Go figure. ;)
She (thankfully) ain’t gay, and the guy she’s married to takes good care of her and isn’t a bad guy. He’s also a competition-class pistol shooter....yet, he’s as liberal as my sister.