There are always multiple ways to skin the cat, sure you could always just copy the files over - use a batch file as suggested. Get some software like sync toy, use rsync, Save the files on a thumb drive and sneaker net them over.
But here's the thing hands down your not going to get simpler than using one of the cloud sync services out there, be it drop, be it google, be it box, be it sugarsync, live drive, etc. etc..
Now I have accounts with most of these, and I like drop the best - it works, its simple! And I have like 70GB of free space with them
And I know for sure it has lan sync and works for stuff like this for sure.
Maybe your wife is a power user, I have to assume not or there would be no need for your question in the first place because she would know how to access her saved files across your network, etc. Since that is not the case - clicking a batch file to copy the files over might be stretching her skill set??
Setup dropbox, and forget about it - it will auto keep the files in sync as they change with nobody having to do anything! She can play here game on her lap top, close the game and in a few minutes go over and play it on your PC where she left off. And then back to her laptop and resume how it was last saved on your PC, etc.. Its a NO BRAINER!!