how can I remove my debit card information from a Kindle given as a present to a friend?

Hello and Good Evening Everyone,

             I purchased a new Kindle from Amazon and gave it as an early Christmas present to a friend.  Earlier today, she made an Amazon purchase from the Kindle.  Whenever she did that, my debit card information along with shipping address popped up by default.  Also, I get email confirmations whenever she downloads apps for the Kindle in addition to any online purchases made from Amazon.  While we certainly trust one another, it is still an uncomfortable and even alarming situation because of the security risk.  With this important point in mind, I am needing any step by step instructions for correcting this issue.  Earlier today, I was able to remotely change the name of the Kindle from George's Kindle to Kathy's Kindle by logging into  Amazon using my login credentials.  The steps used are as follows:

1. Go to http://amazon.com/myk and logg in
2. In the middle left click on "Manage Your Devices" under Your Kindle Account
3. You'll see your devices with a little "Edit" next to the name of each. Click on that to change the name.

       These steps were given to me within another of my open post.  To me great satisfaction, it did work by allowing me to change the name of the Kindle.   Hopefully, the steps oulined will be instrumental in helping to get my debit card information out of the Kindle.  

        Any help given on this matter will be greatly appreciated.  To be perfectly honest, I am not sure how all of this confusion began in the first place.  The Kindle was to just be given to a friend as a present and for her to setup as she saw fit.  

         At any rate, I look forward to hearing back from everybody.

         Thanks

         George