Cann someone pplleeaasse help me. Easyy 10 points?

Soo I had a friend (Jean) weve been friends since 2nd grade and we're in 9th grade. But Jean has been hanging out with this girl (Shawnie) lately. Since Jean and Shawnie have been hanging out Jeans been acting really different. Like one day me Jean and Shawnie mad plans to go to the mall. Soo I told Jean to txt me so we can make plans. And she said yeah i will. Soo all dayy im waiting for her txt but she neverrr txt me. But i go on facebookk and i see Shawnie with all these pictures and statuses about how much her and Jean had fun. Then I started to get mad because she like blew me off because she want to chill with Shawnie (a girl she just met last year). And i mean im not that sensitive of a person if she didnt want to chill with me i would understand, But she could even txt me to tell me she didnt want me to go. Soo me and Jean stopped talking because of it. She just changed into a fake person. But ive known Jean since 2nd grade. Idkk what to do. Shes even doing stuff like walking out of school. And shes a 4.0 student. When everyone was calling Jean a hoe I stuck up for her. But then she kicked me to the side. I was making my friends mad just so Jean wont have a bad name. What do you think i should do? Should i forgive her.? Like idk anymore.