Unless a particular provider has been banned from the property, you shouldn't have a problem at any decent hotel in town.

At worst, to bypass security at the guest elevators, you may have to meet on the casino floor and escort her up to your room or have security call up to your room and let her proceed.

The exception seems to be Harrah's which has been checking photo IDs of everyone at the guest elevators.  This hasn't seem to spread to the other Harrah's properties yet but you never know since it's a mid-term election year.

Bob