It started when I migrated over her iTunes library from her Windows box. The great thing was that not only did it work great (binary compatibility), but that it also auto-found the music (I had it on the M: drive on Windows and I moved it into her iTunes Music folder on the Mac as she has plenty of disk space).
However, the window defaulted to a size larger than her screen, and this is where the frustration started. On windows, this would be fine, as you can resize a window from any edge. However, on the Mac you can ONLY resize from the bottom right corner. You also can't move a window off the top of the screen. No matter what we tried, we couldn't get the bottom right corner on the screen to allow us to resize.
In most apps, this would probably be fine, as the green key would resize the window. However, in iTunes this button switches to the mimized player view.
After some Google searching, I figured out I could use the Option key with the green button, which finally worked. Not intuative or flexible.
Overall, she's still happy, and some learning curve is expected.