I'm mad at my mom for making my neighbors pay me less for dog sitting
How is that your mom's fault?
She told them that if they paid me less she will not say anything to me.
It's understandable that you'd feel angry over losing money. We should always want to get paid the full amount that we are owed.
Haha, just kidding I was joking. She didn't need to give a discount to the neighbors.
I'm not sure I understand what you mean.  If you were joking, and they are paying you a fair amount, then that is great.  However, if you think they are underpaying you, I suggest that you ask them for what you think is fair, or even try to find other dog sitting opportunities instead.