She can do it.
My explanation below is complicated, yes, but it's 100% accurate.
Every Disney resort guest is entitled to one ride from the airport to their own resort on or after their check-in day, and is entitled to one ride from their own resort to the airport on or before their check-out day. There is NO RULE stating the rides must be done ON your check-in day and ON your check-out day. It's a faulty assumption to say the rides must be done on those days.
Since she is driving to and from Disney herself, she will not need the DME rides on her own check-in day and her own check-out day. She won't be using them up, so she still has them coming to her.
There is absolutely no restriction that the rides be done in conjunction with flights. If you want to use your one flight from your resort to the airport, there is no need to make up fake flight information. You can want to go to the airport to get a rental car. You can want to go to the airport for take-out breakfast.

You aren't limited to getting a ride to the airport only to catch a flight.
She must speak with DME directly (866-599-0951), because the main reservations folks at 407-W-DISNEY won't understand and will just tell her she can't do it.
But following Disney's own rules, she will certianly be able to do it, as long as she makes the proper reservations and deals with the cast members (of DME) who know how to hook her up.
If you post this same question on the Transportation forum, you'll get a dozen answers similar to mine. DME has very specific rules that don't always jibe with common sense, but there are those of us who hang out on the Transportation forum who understand all the dumb little details.
