Can roommate sue ME for rent?

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A friend and myself moved into an apartment together. We are both on the lease, and we split the security deposit.
She got a money order and her name was on it, and we gave it to the landlord.
We agreed to have my sister move in shortly after. Recently they've gotten into arguements and my sister tried to fight her after my friend began insulting her.
Litter appeared in my toothbrush, my sisters toothbrush, and all over my sisters clothes. So I told my friend to leave by friday.
WHile I was gone my sister broke down her door and put all oF my friends belongings back into her room. I found the litter and left my friend a note stating that she needed to leave by friday because she's putting litter all over everybody's things and she wanted all her stuff in her room so we did it for her.
She called the cops, and even though i didnt break into her room, because I put 'we' on the note, (like an idiot), I am getting charges pressed.
Now she is talking about how she's moving out and is going to go to small claims court to get the security deposit back from me if the landlord wont give it to her.
Considering all that has happened, does she have a case?