My question involves criminal law for the state of: Florida

While at my girlfriend's friends condo, her and her friend got into an argument. I decided it was time to leave when the shouting began, but my girlfriend decided to use the bathroom one more time. I said I was going to wait outside, I then heard yelling and a loud crash from inside. I reentered and saw her friend straddled on top of my girlfriend with her forearm in her throat yelling at her. I went a pushed her friend off of her and held her down with one arm while my girlfriend got up and we left. The other female then 2 days later filed a complaint of battery against me. My girlfriend and I took pictures the next day of her bruises on her neck and arms. We also have a picture of the girl in a bathing suit the next day without any marks or bruises from Facebook. The only thing that she has is the account of her two brothers that just sat at the table and did nothing. How much weight would her brothers witness statement hold up against my girlfriends and the pictures of the bruises and of her not having any marks? Also, would a DA even pursue this or drop it?