It is impossible to predict if there will be 'major problems' with her, as some people just have volatile personalities. If there are no court orders in place, he will need to retain counsel and file a Suit Affecting Parent-Child Relationship. If there are court orders in place, and since he pays child support, there probably are, then he needs an attorney in the jurisdiction of the orders. He would need to file for modification of conservatorship, and enforcement of the possession order. Good luck. TC
Since there is a child support order that your husband is following, I presume there is some existing order regarding parenting time? If there is, what does it say, and very importantly, what state issed the order?