Is this a power window (electric)or manual.
If your a bit mechanically enclined you can probably make this repair but it does take a while so be ready for a 3 hour or more task.
I will assume for the moment its electric. You will need to remove the door panel carefully. They are plastic and can be easly damadged.
Once the panel is off you should see a weather shield - usually heavy paper stuck on the metal surface of the door, remove carefully and lay aside.
Get yourself a good drop light or flashlight and look inside the door through one of the openings. You will have to determine if one of the rollers has broken of simply come off the window track, also, on some model fords they use a cable system instead of the plastic rollers. In any case you will need to raise the window back up to the closed position by gently pushing on the bottom of the glass until its fully closed. Have someone there with you if possible to help lift the glass. Once its fully closed take a couple of pieces of Duct tape and stick them on the glass, take the other end of the Duct tape and stick it over the top of her door. This will keep the glass from falling back inside the door.
If her car has power windows and you find the cable broken go to your nearest parts store and purchase a new cable assembly. There not to expensive nor difficult to install. The power motor will have to be disconnected so be sure and unplug the connector BEFORE making ANY repairs.
Manual window have plastic rollers that sometimes get off track and even break off their axle shaft. New roller with the shafts attached can be purchased at any auto window repair shop.
Take your time and study how the window regulator is installed as well as how all the braketts work.
If you determine its more than you want to get envolved in any auto window shop can make repairs.