Your only hope is if there is a backup file. You can look in her /home directory or possibly her /home//Documents directory and see if those files exist. In your file browser menu, go to View-->Show hidden files because sometimes backup files aren't shown but are hidden.
If you don't see backup files, and the original files are overwritten, it would take an FBI Forensics lab to pull them back.

If you don't mind using command line applications, you might want to check out a piece of software called Foremost. It was originally developed by the Air Force Office of Special Investigations to recover deleted files, and should provide you with the means to do something similar to an FBI Forensics lab.

Beware that using this software to recover data takes a lot of time. First, the program will have to scan through an entire partition to look for known file formats. And after that, since the software recovers file contents but not filenames, you have to figure out exactly which of the discovered files you were looking for.

Also, don't forget that there is always a chance the computer might have overwritten some of the file data on disk; so the original file might be partially or completely corrupt.

The software is available here:
http://foremost.sourceforge.net/