She doesn't say what make of car she has but they are all fairly similar. DUmmie_GrannieLibTard says that she can get the window up by "jockeying it" so the motor presumably is still working. The mechanism can be accessed by taking off the door's inside panels. There may be a clear plastic cover to peel back also. There is an electric motor driving a gear that pushes a linkage that's connected to the window that pushes it up or down. Like this:
http://auto.howstuffworks.com/power-window1.htmThe windows do fall off their tracks sometimes either at the gear or the slide, usually the slide. Anyway, there is usually an adjustment screw of some sort that you can loosen, put the window back on track, then re-tighten the assembly.
Yes, this is can be a DIY project for anyone with a little bit of skill but be forewarned: Those assemblies are
really greasy! Have plenty of rags available.
Hope that helps