can a husband require his wife to stay in texas with their kids

I'm not a Texas lawyer.  For advice you can rely on, you should talk to a qualified attorney who practices family law.  One place to start looking for one would be our website, http://attorneypages.com

There are a number of things an attorney would want to know, before giving you advice.  In general, a husband has no right to tell his wife where she can or cannot go, although if she leaves it is probably grounds for divorce, after a time. I don't know how it would affect the wife's health insurance, if she gets that through her husband.

The children, though, could be another matter. If there have been any court orders entered about the children, or if a divorce case has already been started, taking the children out of state without the court's permission is a very bad idea.  The courts do grant permission for that, at times, if there are fairly good reasons and the husband's right to see his children can be protected.

Trying to get the court order in the new state almost certainly won't work.  Unless the family moved to Texas only very recently, Texas would be considered the children's home state under a law called the Uniform Child Custody Jurisdiction and Enforcement Act, or UCCJEA, which I believe has been adopted by every state in the country.  That law would prevent the courts of other states from doing anything to help the mother.