how do you know if a girl likes you?

I'm posting this anonymous cause she might find me, lol. But anyway, i'm bisexual and I really, really like this girl. She used to tell me that she's only had a crush on one person. (she's lesbian) She always calls me her "best friend", and laughs at my jokes and like we're really touchy with one another? and we talk a lot. i talk to her more than my best friend... but that's probably just because i like her. Idk, most of it might just be a friend thing. I'll never know, lol. Help, maybe??

if you say i should just ask her, i kind of can't? she's one of my REALLY close friends and i don't want this to ruin our friendship at ALL. also, it's not allowed in our friendgroup to date other members, so i'm kind of stuck.

another problem is that she hasn't liked anyone in that way... for a while. atleast, to my knowledge.

please help me. i really like her.

btw, we're both freshman.