My friend is still using her 3GS. It does not run iOS 7, obviously. She is upgrading her phone to a 5c tomorrow and we'd like to back up all her data (contacts, mail, notes, texts) so that it can be restored on the new phone. Is iOS 7 going to be an issue, considering the software she's got now is older? Would it be best to use an iCloud backup or do it through iTunes?