This is a question about itunes so if you know alot about it......?

ok so my sisters labtop is basically the home computer and we do everything on it....theres one itunes thing and she has a ipod touch and a regular ipod...i have an 80 gig ipod, the bigger one, not the nano. and i have to share a library with her so all her dumb songs are on my ipod and the songs i like are on hers....she complains about the rap and stuff( shes 20 years old) and i dont like the kelly clarkson and ish, well is there a way for me to make a seperate library or sum and bring all the songs to that library and delete the ones i dont want and put new ones on there so they wont be on her ipod too.....