Friendship

So I have this best bud, who is having trouble with people that she thought she could trust which they turn their back on her and got her in trouble.
She was in a friend group with a total of 8 people from 8th grade to 9th grade which increased to 10 in 10th grade which is the grade she's in now their group name was TRTB which stand for thot repelion and Tongue ball
Anyways the group fell and everyone went their own way
Some of the ex members that are still friends got her suspended for six fucking whole days for something she didn't do and now she's having trouble trusting others and I'm afraid that she might get suspended again for what she'll actually do which is fighting them, she's one scary girl when she's angry and I don't want her to come close into killing them
The thing that got me so made is how she use to fucking stand up for them and keep people from harming them fucking asshole
So my question what should I do and what would you do if you were in her situation?