This is a very good question and you need to be careful about how you restore your data.
If you have version 3.0 or 3.1 (if 3.0 you should upgrade to 3.1) you can save the files as a seperate library. If you do not have version 3 your need to save the wife's file in a seperate folder so the librbary is seperate.
This should be done with your wife's file prior to you restoring your project. You should also back up your wife's files before you restore your files and immediately after you restore your files check your wife's project and see if any new data was affected.
If it was you can restore your wife's project from her backup and try again. You might want to save her project in a different folder etc.