Songs on my computer & my ipod are not showing up in itunes

Question

Today, my sister and I both updated our itunes to 11.0.1 (12), the most current version of Itunes available. We have home shared for years, and tonight after my sister imported all of the songs she wanted from my library she was unable to view them in her itunes. The weird part is that when she plugged her ipod in, all of the new songs synced. Also, the number of songs she should have for artists show up when she types an artist name in the search box, but whens she clicks on the artist, not all of the songs show up. For example, she only had the song "Lights" by Ellie Goulding, but she imported 20 from my itunes. When she types "Ellie Goulding" into her itunes search box, Ellie Goulding shows up, and then "21 Items" shows up under it, but when she clicks there, only one song (the one she had before) shows up. She has tried typing in the name of a song that she imported, using home sharing, from my computer, for example "My Blood" and it says, "No Results" but that song is on her ipod. She can play the songs she imported from my itunes by typing in the artist name and clicking "Add to Up Next". Then she can scroll through all of the songs that she imported from a certain artist, but is unable to view in her itunes.
Basically, when she imported a song, it is registering that it is on the computer, but she cannot see it in her iTunes.
She uses an Acer Windows computer, and I have a MacBook.

Answer 1

Is the computer authorized for the account used to purchased the media?
iTunes Store: About authorization and deauthorization
What happens when you:
What happens when you try to sync?
Was the iPod previous synced to another iTunes library/computer?
Have you successfully synced from this iTunes library/computer before?
Do the songs play in iTunes?
Do you have the right boxes checked to sync?
iTunes: Syncing media content to iOS devices and iPod        
iTunes Store: Transferring purchases from your iOS device or iPod to a computer