Legal Question in Family Law in Texas

You can subpoena phone records, but all you can see is the from and to numbers for telephone calls and SMS text messages. You can't get the contents of the messages. And if they were chatting over Facebook, Instagram, Snapchat, etc., phone records won't help you at all there.

I'm not sure what your visitation rights issues are. Proving her infidelity may not be relevant to your visitation issues. I'd need to know a lot more about your facts before I could give you any ideas about that.