I would check out the following firstly as MF said check if she is using roaming profiles. If it is a roaming profile it may be corrupt. I have found that when that is the case it is better to recreate a totaly new profile.
Then verifiy if she has restrictions on the times when she is allowed to be logged to the computer. It may be that she is only allowed to be logged between 9am and 6pm for example. After this time windows tries to close the session but cant as the it is locked. The result can be a corrupt profile.
Also make sure she is the only one useing her account. I had a situation once where every morning a user complained that his account was changed. After investigateing we found he had gave his account to two other people. Of course they changed the desktop every time they logged.
In any case dont for the usual details OS domain or stand alone ...........

Edit : HTregz actually you can find your self in safe mood coming out a lock. I've seen it happen a couple of time on windows 2K machines. Do you do automatic updates at night. Like roll out patches maybe that try to reboot the computer. Sometimes when you have a machine locked and you do an automatic reboot like that it seems to screws up the profile and shuts down most of the proccess and drivers so windows thinks it is in safe mode. Of course never got microsoft to admit it was happening. Ps lots of post between the time i started typing and posting so some of what i said is already mentioned.