Dear Duane,
Thanks for your answer. I probably was not clear enough in my original question. I was wondering whether there would be a tool to do this automatically on a daily basis. I have a network drive and I have time machine (both imac and macbook run their back-ups on the same time machine and are on the same wifi network provided by the time machine.
About the manual processes you described in your answer: If I do that under my user name, will my wife not have user right issues when accessing the files when she is logged in? (at least I remember having all sorts of user rights trouble when doing this kind of stuff manually in the past.