I found out my sister is lesbian? Help?

[Joshua]

I'm a dude. I'm currently 17 and my sister is 25. I was on my friend's facebook screwing around and we decided to look up my sister on facebook. Her profile pic is of her hugging another girl (In a couple kind of way). I just found out she has always blocked MY profile. She dresses like a real tomboy. She wears skinny jeans, snapbacks, and all that stuff and she also has boy hair and a ragtail at the end(not a ponytail). Right now I made another account and looked up the girl she's hugging in the picture and ALL of her pics are of her and my sister hugging and nasty ass comments when they're talking to each other.... My parents are like REALLY REALLY REALLY homophobic especially my mom since she's a super christian. She doesn't like telling me what her job is, etc. I'm not really surprised since it was kinda obvious but I'm kind of speechless and I really need help asking her if she's a lesbian..? Please help!