sister caught shoplifting

My sister is 18, my brother is 24 and his girlfriend is 22. My brother is very verbally abusive. When he gets mad, he scares people. He has been arrested, in jail, probation all that. The other two have never done anything wrong. My little sister who again, is only 18, got arrested today with my brothers girlfriend. Their purses were in the cart at the store when my brother put a bunch of monsters and ammunition into their purses. They didn't know so they bought their stuff and walked out. After the first set of doors, they were stopped and arrested. My brother bailed after he seen cops. I'm more worried about my sister as she is a mother to two, one is a year old tomorrow and the other is only a month old, still in the hospital, born at 24 weeks. The 1 year old was with them when it happened. From what I know, they arrested her, took her to the county jail where she was held for like 8 hours and then let out waiting for court this week. She is absolutely terrified. They said that even though she didn't know, it doesn't matter because the camera didn't catch either of them put it in the purse. All it caught was him having the stuff and her leaving with it. I have no idea what's going to happen, she is freaking out, scared that she is going to go to jail. I'm wondering what I should do to help? Should I call a lawyer?
The total ended up being like $108