Can my wife leave the state with our daughter without my permission?

If there is no court order in effect, than she can take your daughter out-of-state.  However, you can go to court and obtain an order which will require her to remain in the state (or return if she has already left).  If at that point she leaves (or doesn't return) then she can be charged with parental kidnapping.

Taking a child from their home to take them to live in another state without a court order is not a good idea; either now or in the long run, insofar as a custody battle is concerned.  What you want to do is get a temporary order from the court on custody and visitation.  It will be temporary because a final decree will only be issued upon divorce.  The court will consider the bests interests of the child in making its determination. The court will look at the age of the child, the relationship of the parents and the child, the present living situation of the child, etc. 

Note:  She could file for custody once she re-establishes residency in her new state (but that will take time).  However, if she does, then any custody hearing would be in that state.  So you really should go to court first.

Right now, you need to consult with an attorney in your area as to all of this.  They can bet advise just what to do under your specific state law.