You should be able to see your iTunes library from your wifes iTunes.
I think that is "Library" sharing, as opposed to "Home Sharing"
Library Sharing is Edit>Preferences>Sharing and then you can tick/untick "Look for Shared Libraries" and "Share my Library on my local network"
Both of mine are unticked and my Wife's iTunes also has them unticked (although "Look for shared libraries" is ticked on my laptop).