Of course a lot depends on your wife's interests and there is a great quantity of choices available. I am not familiar with security issues with the iPad, but if she likes reading various types of news, Flipboard is an excellent app for the purpose. It will work on both the iPad as well as android devices and is free.
I would just Google "Best iPad apps" and go through the resulting lists and make choices from there. Gizmo's Freeware is a good place to start.http://www.techsupportalert.com/best-free-ipad-apps.htm