Force Erase everything on iPhone 4s?

I updated my iPhone 4s to a 5s and restored everything from my cloud, I do not use iTunes. I'm trying to Erase all media and settings as I'm giving my mother the 4s to use. When I select 'Reset' then 'Erase All Contents and Settings' it makes me put my Apple ID password in. When I put it in and hit erase it literally does nothing at all. I can go about doing anything on the phone. I know the password is correct because I use it daily for other reason on my new phone. Is there a way to force an erase all?

Settings > General > Erase content and settings > confirm