I disagree, to a point, on Linux is not like Windows.
For many, of your everyday computer user, that just want to create Office files, Print, Browse the Internet and read Email, they are no longer very much different at all, pretty much ready to go out of the box, for the most popular distros. The only real exception is drivers for some hardware and WiFi, but that also can happen on Windows.
I was given a fairly new laptop that the hard drive had failed (already replaced two under warranty) and Battery was at 1 hr max. For the price of a good hard drive and battery (under $90 USD) and (free) Ubuntu 13.04, I had a working laptop, that I gave to my Windows XP using wife, she has had very little problem using it with little to no input from me.
With the slightest bit of learning some terminal commands, you can kick Windows to the curb easily. Even that may not be necessary, there are just certain things I like to do with terminal, for all I know, it may be easily done through the GUI.
A little more info on the purpose and you and your wife's computing needs and computer specifications, we can probably narrow down the list of distros you might want to try.
I would say start with latest Ubuntu relatives, (you will most likely want the LTS of any distro, if available), in no particular order...
Zorin OS
Ubuntu
Ultimate Edition
OZ Unity
Xubuntu
Kubuntu
Linux Mint