TexasCHLforum.com

If you are a student and attending an out of state university, you may maintain a residence in your home state. You will have to keep a permanent address here in Texas, like your or her parent's home.

However, if it makes more sense to change your address to PA, then you can just change your Texas CHL to the PA address and have a non-resident license. Once you move back, if it is still not expired, then you just change your address back to the new Texas address and it becomes a resident license again.

As far as Texas is concerned, the difference between a resident and nonresident Texas CHL is the address on the card. If the Texas address is where her husband or parents live, I believe she can say that's her "permanent residence" while in school and not update the address on her DL or CHL. Otherwise, it may be cleaner to pay a few bucks and update the address to PA.