There is this girl.How can i tell if she likes me?

Well there is this girl that keeps coming over to where i eat during lunch and ask's to touch my hair. She is really pretty and I am really shy. Yesterday her friend came over with her and said she needed to talk to me. The girl that i liked was with her and she said "EWWW why are we even over here" and walked off. which disappointed me and then her friend walked off.. but today she came again to come touch my hair. How can i tell if she likes me or just wants to touch my hair everday... :( She dosent seem shy around boys so I think she really just likes my hair but hoping she likes me becuase i like her. Please help :) ty