Hi there, brooklynn65.
I see that you're having a problem making in-app purchases. You believed that your purchase would use your payment method, but it used another's instead. But there wasn’t sufficient funds to cover the purchase, and you can’t buy anything now. I’m glad to help with this.
Family purchases and payments -- I believe you're part of a Family Sharing group and your Aunt is the organizer. This means that any purchases by the family is charged to her payment method.
If your payment method is declined in the App Store or iTunes Store -- Since there wasn't enough funds on her payment method to pay for your in-app purchase, her payment method was most likely declined, and this article provides the information and steps to fix it.
Payment methods that you can use with your Apple ID -- This article provides the information regarding the payment methods you can use. Be sure to review country- or region-specific information under "Payment methods by country or region".
Add funds to your Apple ID -- If you wish to pay for your own purchases, you can add funds to your Apple ID. If there's sufficient funds on your Apple ID, iTunes will bill that first: How App Store and iTunes Store purchases are billed
Take care.