It is easy enough to create a new Apple ID and use it. There are some things she should be aware of before doing so though.
She will no longer be able to share apps, books, and to some extent music and movies. Purchases are associated with the account, so she will need to pay for her own stuff. While it is possible to have two accounts in the same iPad, it's a pain when it comes to updating music, apps, books, whatever. I'd avoid it unless you have no other solution.
She will want to have her own iTunes to sync with on a computer (if she uses iTunes on the computer). This can be done either by having a second login on the same computer, or using different computers. Otherwise things become a big mess. It's even harder to keep multiple accounts straight in the same iTunes library on a computer than it is on the iPad.
She will need to go to each of the iStores (App Store, iTunes, iBooks) on the iPad and log out then back in. You can find the Apple ID at the bottom of most store pages. Tap on it to access the account login and other options.
If all she wants is separate backups, syncing, and content through iCloud, you can have separate iCloud accounts while keeping the same iTunes account.
Apple IDs and iCloud
Apple IDs and iCloud
Hope that helps.