You want to transfer the music from your iPod to her iTunes library or her account? If it's the latter (her Apple ID), then it's not possible as purchases made under one Apple ID are permanently attached to that ID.
If it's the former, see this older post from another forum member Zevoneer covering the different methods and software available to assist you with the task of copying content from your iPod back to your PC and into iTunes.
https://discussions.apple.com/thread/2452022?start=0&tstart=0
B-rock