that's just bizarre. You're saying that she will make change to a document, then try to open it, and changes are gone on HER laptop , but you open the very same document from another computer with 2010, you can see it? WTF??
1) Does this happen on a fresh blank doc file?
2) Is she saving to network drive or other removable drive of any sort?
3) Does she have compatibility pack for 2007 install in programs and features? (normally this can be removed if present)
4) what if she tries to save as a word 2003 file?
5) Have you run office repair from programs and features?
6) Do you have legit version of office 07?