If you both open iTunes and turn on Home Sharing (and are logged into the same account) you should be able to see her library in the left hand column. Click on it and it should then display in iTunes on our computer. Highlite the songs you want and click import in the lower right hand corner of iTunes. If you already have songs in your iTunes you can go to the lower left of iTunes and click Display only those items not in your library. That way you can avoid importing duplicates.