If she has not created an iCloud account then she does not have iCloud set up on her iPhone. Still, an iTunes backup can be made in lieu of an iCloud backup.
As far as I know, you need to create an Apple ID when setting up a device for the first time. Unless she used your Apple ID she had to create her own. Any time you have an Apple ID you also have an iCloud account. Weather or not she's signed in to iCloud, look at her phone.