I'm going to make a girl cry even though she was picking on me
What is your reason for wanting to make the girl cry?
She was picking on me.
Picking on her for bullying you is not a great way to go about it. I am sure you do not want to be considered a bully like that person.
I'm going to make her cry.
Do as you please, just be careful not to bully someone. You know how you felt when being bullied, so putting this on someone else is not a great way to appease the situation.