What do I do? Daughter takes revenge

I'm a momma of 3. Two boys 19, 10, and a 5 year old girl. I'm not a helicopter parent. My kids play outside, unsupervised, in or out of mud as they choose. I encourage them to stand up for themselves, each other and friends. I get lots of compliments about my kids. There kind, they ask before doing things, and are told they are welcome anytime at their friends houses. My daughter is very head strong, I call her a force of nature. She is a thinker too. She told me she was going to marry grandma because she's my boss and that would make her my boss too. So here is the problem, 6 months ago a boy threw a rock and hit her in the eye. She told us about it, his parents talk to him, he apologized.He's a good kid and at our house all the time. This morning he was over visiting my 10yr old son. She peed in a cup, loured him in and dumped it on his head. She was proud of herself. She felt like justice has been served. I got the boy cleaned up, she was sent to her room and later came out to apologize. I talked with her about what she did being disgusting, she is cleaning up the mess. I talked with her about it being good to stand up for yourself but not holding a grudge. He had already apologized and I thought we had moved on. She obviously had not. She made a plan with this. She thought it out. I'm going to be locking my bedroom door at night now until forever. The look she gave me while I was talking.... How do I tell her she can stand up for herself, but it needed to happen 6 months ago. AND that throwing pee on someone is not ok (unless they did it to you first). ?? She's 5! via /r/Parenting https://ift.tt/2NBERvY