Can I put a stop to my child visiting her dad because of his new wife who my child doesn't get on with? Who is making her life hell.

Yes. Go back to Court, file for a change in visitation, provide PROOF that the situation is a danger to the child (physicaly and emotionally). The Judge will listen to both sides of the story, very possibly appoint a guardian to represent the child legally and deciede what is in the child's best interest.

They will take a close look at your feelings toward the "new wife" and make sure you aren't putting words or feelings into your child's head.

Judges are reluctant to terminate visitation of children to a parent. It is more likely another arrangement can be worked out, but it is understandable that your child will not like your ex's new wife and possibly making up stories. How old is your child?

Tick

Have you ( and new partner if you have one) sat down with ex and his new wife and discussed this

I did not go through courts at the time(9years ago) was lucky to arrange visits through my solicitor at the time.I have brought this up with ex husband but he not interested plus he does not talk to me hardly ever.. my child is coming up 11 this year and have decided to allow her to say whether she wants to visit , but I feel that he would take me to court if she didn't go.I have never stopped her from going over even from when she was small, but now she is growing up and having a opinion, I just don't know what to do for the best..

You are in the UK? I am familiar with US law.

I'd contact a solicitor - wish I could help but I really have nothing else to add.