I lied to my aunt about her DNA test
Why did you lie about the DNA test to your aunt.
She told me that she would give me money if she was related to my mom
This test was going to determine if your aunt was biologically related to your mom, and you lied to her about it. That is horrible and is not worth any amount of money. This test can mess up family trees and medical procedures because you gave her false results.
Relax! I was joking about the money. She's my dad's sister, so it was an incest type joke that clearly went over your head!
Even that type of joke doesn't seem appropriate. Perhaps your family thinks it's okay to make jokes like that, but you need to be sure before you say anything. I'd hate to see a joke cause real problems and strife in your relationship with your aunt or parents.