How many backups does iCloud/iPhone store on the computer?
My sister's iPhone 4S downloaded the most recent iOS (iOS 8. Something rather) without her telling her to do it at any point in time, and it's pretty well ruined her phone at this point. She can't upgrade or get a new phone for the next 4-5 months, and the phone with the iOS 8 has made it to where it's very close to being nothing more than a paperweight.
I'm wondering if anyone knows if multiple backups are stored on computers and if it's possible to select an older backup that has iOS 7 or 6 on it and apply it to the phone so it goes back to a software the phone can better handle?
Any help/feedback/advice is greatly appreciated.