Question to OP: Did you let UA know in advance of a medical reason for aisle on right side of aircraft? I wonder if the GA knew of this in advance (noted in PNR) whether GA would have swapped pax in 2C for 1B and let hubby have 2C or something like that. Family would be split, but hubby would get right side aisle. Like others said, these things happen and letting UA (or any carrier) know of a special need in advance is likely to help.