score:3
Some airlines, like American Airlines or Delta allow name changes before the flight. Firstly, you should check with the carrier if (and how) can you correct your mother's name. If it is not possible, she should bring her marriage certificate along with other documents that show her maiden name and her married name. Here you can check a real history (and some tips) from a just married traveler. She had no problem traveling with a ticket printed with her maiden name.
Upvote:3
Your best bet is to skip the guessing game and call the airline to explain the situation as fast as possible.
If they will not accept her as is, they might be able to come up with a solution for her.