There are only 15 ground floor rooms (not counting villas), all are located at the South end of the hotel.
Second floor rooms are more abundant, but areas over DTD do not have second floor rooms. The stairs to the second floor off the lobby have a beautiful design, but there are also enclosed stairwells throughout the hotel reaching all floors (although not so beautiful).
OP: If your aunt is OK using stairs the GCH should easily be able to accommodate your requests for a ground floor or second floor room. If you aunt must have a ground floor room, you might need to "escalate" the issue since your need a guaranteed ground floor room. The GCH does not guarantee requests (view, bed type...), however Handicap Accessible reservations are guaranteed. Inform the hotel in advance about your special needs.