I was going to re-register my mom's Kindle to my account so she'd have access to my reading list but wanted to do it online since she get's flustered about doing it on the device. I deregistered her device on her account, but when I then went to my account there was no "register new Kindle" button. I know it used to be there, but Amazon seems to have either hidden the capability to enter the serial number yourself or they're no longer allowing that. Is this capability now hidden somewhere, or does it just no longer exist?

And BTW, I hate that new Manage Your Content and Devices page. It has that stupid drop down header that suddenly hides everything as you scroll down.