i think it would.. but then again it would be silly if it didn't as when you start to update your phone all the changes will start appearing on her cloud devices.
you could change the cloud setting in settings/icloud and then delete account from the phone first so that it didn't wipe whatever was in the cloud first
disclaimer: I am only taking an educated guess here.. i take no responsibility for any loss of data from actions taken as a result of this post, might be best to check with an apple genius at an apple store first?