Can anyone help please? 
Last year I set up an Amazon account for DD to get books for her kindle.
I've just tried to buy some books and they're not appearing in her library on the Kindle. So, there's a problem.
But - I cannot for the life of me find ANY information as to where her account details are. I've tried her email address but amazon says no account exists in that name.
I've searched and searched but nothing!
I'm such an idiot as usually I keep all this kind of info in a file on my phone.
What can I do? (Apart from deregistering the kindle, and starting again, which I'd rather not do as I'll lose all the books on it.)
Help!!