OP, I'm thinking the story as presented might be too complicated for the airlines. How's this one fit:?

My best friend is getting married and I gifted the happy couple 2 FF tickets. I made the reservation using his last name. I did not realize that she won't be able to get a new passport between the wedding date and the honeymoon. What are my options?

Simple, concise, and throws it back into the airline's lap. Doesn't get into the whole "not changing names" stuff and all the other family drama.