My step daughter (16 until 9-17) wants to choose when she see her mother. The mother intentional adds mental stress to the daughter even being made aware it is hurting her and still continue.

The custodial parent must make the child available according to court visitation order. But they don't have to force the child to go with the NCP.

If the 16 yr old objects to going, then you should go back to court to modify the visitation order.

The custodial parent can be taken back to court for a hearing of being in contempt if the child does not go. The defense will be the child does not want to go.

It will be up to the judge to decide if they accept this or not.