There are plenty of sites where you can upload her music -
SoundClick - Free MP3 music download and much, much more.,
Last.fm – The Social Music Revolution (recommended),
MOG - Discover people through music and music through people,
MySpace, etc.
TuneCore: Welcome is one of the services that gets you into iTunes and other paid stores
If you want to sell CDs online, I recommend
CD Baby: let's find you some great new music... (they can also handle iTunes & co for you)
BUT! BUT! BUT! You do need to ask her permission first. Legal issues aside, it just isn't courteous to do this behind her back.