Most Helpful Girl
Stop being selfish. You need to stop being desperate for somebody you barely even know as a friend. You need to truly get to know her for her. Maybe to you, she is flirting, but it could be that she is just being friendly and you take it as flirting. Either way, the same way a girl can't force a guy to like her, is the same way you cannot expect her to see you the same way. You just need to be honest with her but be prepared for a lot of awkwardness afterwards and possible lost of friendship if neither of you can be friends anymore. There is a reason why she sees you as a brother.
Most Helpful Guy
Bro, express ur feelings.
Otherwise hw would she even know that u have feelings for her