Ex telling child to leave

Hi. This is my first post here. I have a court order for my now teenage daughter. She has lived with me full time for 4 years and goes to her mum's 4 times a year.
I got a new partner last month. She came on a Friday and my daughter left for her mum's the day after.
The relationship lasted only till the Sunday when I was grabbed roughly and called the police. They took her away but I didnt press charges and after 2 weeks I allowed her back. The relationship lasted another 8 weeks and she's gone again after I caught her video chat to other men.
Now during the first split on the Sunday which lasted 2 weeks, the girl messaged my ex wife and told my daughter not to come home and stay at her mum's because I am abusive and she's rang social services.
So now after the 8 weeks we split up and the girl send me screenshots of the conversation she had during the first breakup showing the girls messages to my daughter telling her not to come home.
Is this classed as a crime? She had no reason to message my ex wife or daughter and I told her not to while she was here. We split up and didn't get back together for 2 weeks but in the first few days of the split we weren't even talking and she's send these messages to my teenage daughter telling her not to come back to her dads.
Can anyone shed some light on the crimes commited please?