Open Question: What should i do? Need honest advice (easy points)?

I've known this girl since i was 5 years of age and she and i have been good friends till now and we are 14 years old. Her parents are good friends with mine and we've been no more then friends and i regard her to be very close to me in the sense of something akin to a sister-brother relationship. She is very pretty and is quite popular but ever since we entered middle school we've been expanding our relationship with other people, but recently she's been hanging out with me more and more frequently and talks to me alot and watches as i play basketball and she's got alot of friends. She sits next to me during lunch and in class too. One of my friends are annoyed because they don't have time to stick around with me because of her. Is she hitting on me? She doesn't mind our arms rubbing against each other too lol I'm 14 look alot like my avatar (no sriously ill try n get a pic in) and am 175-178 cm tall. This girl is also 14 and around 172cm tall. she and i are both from the same race