Did you get Amazon Coins?
Seems that by letting my mother use the Kindle Fire that I bought her on my account (Amazon thinks I love Romance novels, by the way). I was sent 500 Coins. These are VIRTUAL coins and worth $5.
"as a thank you for being a Kindle Fire owner, we have given you 500 Amazon Coins (a $5 value) for free. Use your coins to purchase apps, games, or in-app items from your Kindle Fire, or from the Amazon Appstore for Android on Amazon.com."