Unless there is a local dealer that is authorized by Rolex to do repairs, I'd use the Dallas service center. Many non-authorized repairman can not get Rolex parts and use substitutes or counterfeits. Plus if it ever does go to an authorized service center later on, Rolex may insist on changing out any non-Rolex parts at your cost before they do any work on the watch. Or if it is still within the warranty, using a non-authorized repairman may void the remaining warranty.
How long has she had the watch? If it's been 4 or 5 years, it probably needs a service too (cleaning, oil, etc.). If so, another reason to use the Dallas service center.