Best wishes to your wife and her recovery.

You might try e-mailing or Skyping the property directly (there's probably an e-mail address on their property page on Hilton.com), and ask if you can reschedule for a later date if you have any plans to eventually make the trip. I've found properties are often happy to reschedule non-refundable rate stays, often by up to a year. Worst case, you can at least let them know the room will be available.