Your ex husband's girlfriend's child puts hand on your child what would you do?

This isn't a one time incident they had been together for a year. My 6 year old daughter was going to her dad's place every weekend prior to him moving in with her and after maybe the third weekend of the girlfriend and her child being there my daughter came back with a long scratch on the left of her face. My baby said the girl scratched her on purpose but her dad insisted it was an accident. I didn't let it go because I got a bad feeling. A few weeks go by my baby comes back with another scare, more scratches on her face and dad downplays it again. I went to the police station to document and take pictures. There's a court order for visitation I can't stop the visits. A week later my baby comes back her lip is swollen and she was so happy to come home. She told me that the little girl is a bully always hits her for no reason again her dad does nothing. I document and have the cops take pictures once more. She got the busted lip because her dad left her in the car with the little girl for 10 minutes supposedly in a Walmart parking lot. At that point I'm in lioness mode I'm not trying to hear nobody downplaying bullying my baby I need results. Her dad makes me out to be crazy and they're just kids that's what they do. I have 3 kids total my little ones don't do that. The little demon child is obviously disturbed and she will further traumatize my child. I called my lawyer and took it back to court it was a long shot but my ex is not smart. He admitted to the judge he does not watch the girls 100% of the time so the judge suspended his rights and recommended parenting classes upon completion he'll consider supervised visits. Child services got involved idk what they found out but the girlfriend is pissed at me she wants to fight.

I feel like a failure I knew something was wrong the moment I saw the first scratch. I could've said screw the court order but I didn't want to reap those consequences. I wanted to fight both of them but again the consequences. Child service helped me out with a therapist for my baby for a year to help her through this she just had her second session this past Thursday. She's been sad she'll cry herself to sleep sometimes so my husband and I go sleep on the floor in her room. I bought a speaker to play the sounds of the ocean and a night light that that displays all the planets, her favorite. It's helping. Her dad is dragging me through the mud yet he did this to her his own flesh and blood. Before this girlfriend came in the picture he was a solid dad but she came and he started acting like a fool in love. She had his nose so open if it rained he'd drown.