I got tickets using airline miles for my parents to fly round trip, they have used the first leg of the trip. We knew the changes of having to change the tickets was high as this was for medical reasons. Right now the Drs have said they want my Dad to stay where he is for at least 6 months. Since they didn't plan on this when they left and the tickets won't stretch to 6 months my Mom will use the return ticket to go finish business at home. My sister is planning to go with her. It would be great if my sister could use my Dad's return ticket. I've told them I don't think it can be done but that I'd ask the airline. Wanted to know if anyone has heard of an airline doing this? Sometimes I can get different answers from different agents so wanted to have some idea if anyone has had success with this.