My initial answer is no, the step-mother does not have any rights to visitation. There are limited procedures for third parties to secure visitation rights in Florida, but that is generally grandparents and that would be by agreement or Court order. In this case unless there was something in the agreement or order that allowed the step-mother to exercise his visitation in lieu of the Father, I would say that simply having visitation does not give him the right to transfer it to another party.
It is perfectly acceptable for parties to agree on varying their order, but it is not a right for one party to do it on their own.
I would be very careful about allowing the step-mother to have visits as it could easily develop that if it were allowed to occur and in the future they attempted to go back to Court, it could be ordered.
As well, it is troubling that she is apparently going to go to the school. I would say that you could notify the school that only your or your ex - in person - could pick up your child.
If he wanted this to happen, he could have attempted to change it via Court Order and he didn't.
Now, he may try to threaten you with contempt or violating the Order, but I don't believe that would be successful because you are not denying him visitation, he just isn't there to exercise it and if you say the step-mother can't have it, the Order as you explain it does not give her any rights, so you can't be punished for doing something that was not considered.
I would tell him that you will follow the Order and that since the Order doesn't give her any visits, that is what you will do. I would also tell him that she should not come to the school. Finally, do offer things like facetime or Skype for him to have electronic visits as this will show that you are working with him as opposed to doing like he is.
Please note: This is general information for educational purposes only and is not legal advice. There is no specific course of action is proposed and no attorney-client relationship or privilege formed within this conversation.
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