@raptureman2020 The homophobic point here is... Why do you question her when she says she likes girls and not when she likes boys?
Like you said, she's 8, she's developing and maybe now she realized that she can like girls. Maybe she did before but never said anything about it. Maybe she never liked a girl before. I don't know, I'm not your daughter, but neither are you.
She has to experience herself to get to "understand" everything, as you say. It's not like you get 15 and suddenly get everything out of nowhere.
I know someone who's mom had a similar conversation to her. Mom always said loud and proudly "I support gay 1000%" but when the moment came to her daughter she took it really seriously and gave her the "you suuuure?" that invalidated those feelings for a long time, she even thought it was "just a phase" most part of her life. She was younger than 8.
She told me several times that if she would have been validated at that time everything would have been different for her. Her whole life. She would have been way happier.
Why is ok to like boys but when it's different the topic HAS to be treated really seriously because "she's only 8"?? Really, WHY?? Is she too young to get lgtbiq for you??
She is going to know what she likes and what she doesn't by herself, don't worry about that. She's way smarter than you can even imagine, as all kids are.
Maybe she even ends up not liking girls or maybe she does, but that doesn't concerns you at all.
What you have to say RIGHT NOW is just "oh honey, remember that talk we had?? That was really stupid, I'm really sorry for saying that to you. About your crush that's sad, she doesn't know what she's loosing, you are the best!!" and give her a hug and a kiss, don't even mention the sexuality stuff again, and definitely don't give her a hard thesis about sexuality and a talk just because she said she liked someone that you didn't expected.
Treat it as it is nothing!!!
And bytheway, if the school she's in could not accept her or bullying could be a problem just support her, love her, and get her out of that shithole ASAP.
I'm mad now, I feel sorry for your girl...