Has anyone ever been in this situation with citizens arrest?

OK i already asked what i should do because my brothers girlfriend called the police on me and charged me with tresping and petty theft,when she invited me to stay at her place for the weekend and it was a picture that i gave her of my brother and i took it back and she calls that burglary,any ways i went to the first court apperance that i was suppose to per the ticket i got the night of the incident,at court i plead not guilty and now the whole thing is going to trial im scared shitless because i'm trying to get a job in law enforcment and i cant cacth a case.so when i was at court i saw a really cool girlfriend of mine and she told me that if my brothers girlfriend who had the citizens arrest put on me, well If she doesint show up that the charges will be dropped and the case dismissed is that true?