It was so sweet of your daughter to do such a thing. Well, you need to register your Kindle device if you have to buy or download anything from your Kindle. Also, you can get connected to the same account through other devices having Kindle app like iPad or phone.
Go to Home > tap (Menu) > tap Settings > tap Registration.
You need an Amazon account if you have one choose the option that you have one. Then enter the information about your Amazon account and Register.
If you still do not have an Amazon account, select that option and create a new Amazon account.
Managing your Kindle is a kinda big process, so sit back and read on. You can manage your Kindle by first going to Manage Your Kindle
1. Go to Amazon main page > choose account menu > choose Manage Your Kindle > login using your Amazon account details.
2. Now you can choose how to view your content in Kindle. This list shows all the books, magazines, subscriptions, apps, and personal docs that are present in your Kindle. To filter the way you view, go to Manage Your Kindle page > select View to get a drop-down list. Sort according to the title, author, or date. Do this by clicking once on the column header to arrange in descending order and click once again to get in ascending order.
3. Search for a thing in the Search bar and click go. Get details of the item by clicking on the plus sign.
4. Send books and docs to your Kindle and also from your Kindle. Sending books to your Kindle reading app is feasible not docs. To send a book or doc
Choose a book or doc to send and tap over the book to get Actions drop-down list. Then select Deliver to My and select the device to which you want to send and click on Deliver.
If the device does not appear that means the doc that you are sending is not supported by your Kindle.
5. Download a book in PC and transfer it to your Kindle by making use of a micro-USB cable. Go to the book you need to download and get the Actions drop-down list > select Download & Transfer via USB > choose the Kindle device to transfer > then select Download and save the book using your browser’s download option.
6. There is a feature to delete all unwanted files and books forever from your Kindle. If you delete a book which you bought in Kindle, then in the case of wanting it again you have to buy it once more.
Now go to the book or doc that has to be deleted and get the Actions drop-down list > click on Delete from Library > then click Yes to confirm the deletion.
7. Kindle has this feature of archiving all the docs that you send. This would take up the free space, so you can disable this feature by
Going to Personal Document Settings > click on Personal Document Archiving > select Edit > remove the check from disable archiving > click on Update.