I Miss Miss My Best Friend

We use to talk everyday,now she doesn't even say hi....I know i did not do anything wrong and if I did she would have all ready reclaimed for what I did.We have been Best friends for a few years now she was the only only person I could talk freely about everything.She became my sister and now its like shes a complete stranger to me,I dont know what to do I really miss her and I would like to talk to her before school starts ,Any advise is welcomed just dont be mean its really hard to just move on from the only person that was always there...