Please help! It really is horrible trying to guess. I can't ask her because we aren't friends, and even if we were I would be too scared to ask.
I would say that the only way to know for sure is to ask. You said you aren't friends, how do you know her? Do you talk at all? If you regularly talk, I would try to hint at the subject, like maybe ask about past boyfriends, if she's interested in someone, etc. I'm guessing from your age you're in high school? Even just saying something like "Finding someone to date is so hard, there's hardly anyone I'd be interested in at this school, what about you?" Besides doing that, I'd just see what kind of eye contact she makes. I find there's a different kind of eye contact when I look at straight girls, versus another gay girl. The eye contact between two gays girls basically asks, "Are you gay too?" Look for that. And look to see how she looks at other girls/guys. But honestly the only way to know for sure is to ask. If you aren't friends, I'd suggest trying to change that! And once you get to know her, you'll have a better idea and can maybe even ask. And if she is straight, at least you made a friend.
That's good advice! If I do get the chance to talk to her those would be great things to ask. The only time we ever talk is if we're in the same class though, and unfortuantly this semester we're not. She's very popular, so it's hard to find her alone. Thanks though!
The sad thing is being in high school there is sooo much pressure and to fit in even if she did have gay thoughts she's not likely to share them with you. You'd have to wait until you could be in the same class where you could have a daily interaction with her.
I don't think there's a way to know for sure. Some even say homophobic things to stay off people's radar. Like the posts above have said, get to know her.