Q: how to reset automatic IOS update

Are you absolutely certain your mom has an iPhone 4S?

It turns out the highest version of iOS that an iPhone 4 can ever run is iOS 7.1.2.  is this a coincidence?  Probably not.

You could do Settings > General > About > Model and post the result here.  We can tell you if that is really an iPhone 4S.

you will need to update to 9.3.5. OS 8.1 is no longer available for that system

Update the iOS software on your iPhone, iPad, or iPod touch - Apple Support

sberman wrote:

 

Are you absolutely certain your mom has an iPhone 4S?

 

It turns out the highest version of iOS that an iPhone 4 can ever run is iOS 7.1.2.  is this a coincidence?  Probably not.

iOS 9 is compatible with these devices.

https://www.apple.com/lae/ios/whats-new/

iPhone

• iPhone 6s
• iPhone 6s Plus
• iPhone 6
• iPhone 6 Plus
• iPhone SE
• iPhone 5s
• iPhone 5c
• iPhone 5
• iPhone 4s

iOS automatic update (the downloading part) can not be turned off. There are tricks to turn off iOS auto download if that's what you did. iOS 8 is no longer offered. You will have to upgrade to iOS 9.whatever is currently available for your phone.

Yes, as I stated, if the original poster has an iPhone 4, then iOS 7.1.2 is as high as the iPhone can be upgraded. Otherwise, they can go higher.

Oopss.. I misread your post. It makes sense the second time I read it.

No problem.