I have a visitation hearing pending and want to know if my wife can move with our children?

I assume your hearing is a Request for Orders to Modify the prior visitation orders because your ex-wife plans to move and wants to take the children with her (thereby making a change in the schedule necessary). If so, the Judge will decide whether the children will move with her and visit you, or will stay living with you and visit with her. The two of you will probably also need to try to resolve the issue by mutual agreement before court. If you can't come to an agreement, then the Judge will decide based on how much time each of you current spend with the children, how much each of you are involved with their schooling, their teachers, their medical care, their homework, their extra-curricular activities, trying to determine which home will be in their best interest to try to preserve as much stability as possible in determining their best interests.

There will be up to the court, and what you present to it. You need an attorney.

There really are not enough facts here to give a complete answer. It is important to know whether or not you have any existing court orders that outline custody and/or visitation. In general, she can move within the state, but not outside of the state. If she does move outside of the state, you can bring an emergency motion to have the children returned to the state and to your custody.

In OK, once an order is in place, to move more than 75 miles away requires an agreement of the parties or taking the matter to the court for a decision.

In Nevada, not if you have a joint preliminary injunction and she has been served with.