How do I handle a snooping co-worker who accessed my computer?

I went on vacation for a week and a co-worker, who is the owner's daughter, called and asked for my password so that she could print a form located on my pc. When I returned to work, I noticed that the "Games" menu (solitaire, freecell, etc...) were no longer on my computer so I checked my documents and their access dates and found that in a file labeled with my name... all of the documents had been accessed. These were personal files with nothing too important within them. However, they were personal and not the file she informed me that she needed to print. I accessed the security system and replayed the video on the date of access and found that she was in my office at 4 different times for a total of about 2 hours, all at my computer. Also in my office was her husband a couple of times looking in with her.

This feels like a very serious violation and it made me so mad that I left early and have decided to not return to work until someone calls. Anyone have any suggestions?

One other important little facet to this situation... I asked this person to look in on my house and check my pets while I was away, which she did. She had full access to everything within the house, however I do have a safe for very sensitive material... however, my common records (medical, bills, paystubs, etc...) are simply contained in a file cabinet. How could I determine if she accessed these things since I obviously trusted her enough to ask her to look in on my house for me? I didn't set any "tell tell" signs up or take pictures of anything before I left because I never, in a million years, thought she was capable of this type of behavior.

Unfortunately if the computer was company property there can be no expectation of privacy. I wouldn't trust her with the key to my home anymore though. Although the company had rights to your computer in the office, it was sneaky and only you can decide if it is the type of place you would like to continue working for.

Passwords.....You can even put passwords on Word, and Excel spreadsheets.

OMG I would freak out!!! It would be time for them to find a new employee. I would quit that job. And I would probably kick that (you know what's) behind!!