I NEED TO VENT!!!

So, my MIL came down for Halloween and asked me if we were taking my daughter, who just turned 19 mobth yesterday, trick-or-treating. I said no, that I thought she was too young and that we were just going to pass out candy. My mom alao came down too. Anyway, while passing out candy she asked me if she could take her for a little walk down the street. I said sure...when they came back she had two candies and I immediately thought, no she wouldn't have gone trick or teating without me and my MIL said older kids kept trying to give her candy so I bruised it off. Then before bed, she showed me the two prices of candy and said, "Her first trick or treating candies!" Are you fucking serious!!! How inconsiderate could she be???Why would she think it would be OK to take MY daughter trick or treating without me??? Seriously so pissed off. My husband is out of town for work and I want to vent to him, but I'm afraid he'll say something to her. I should have said something, I just just didn't want to start something.  Am I overreacting???