Hi this is Michelle and i will be assisting you today.
let me know when you are ready to chat.
Log on to Amazon.co.uk, with your wife's credentials.
Under the Your Account menu (where it gives your wife's name), click Your Account
Then scroll down to Digital Content
Select Manage Your KindleClick Your Devices tab at the topThen search for your new kindle in the list, and click the link which says deregister.You can then go back on your new Kindle, go to the Kindlestore and register the device under your Amazon account details.Should you need any further assistance please let me know the model of your kindle. Have a good weekend J