As soon as she starts, walk away. Who cares if her coat isn't on. Start walking towards the door. If you get there, and she hasn't followed yet, walk over to a wall where brochures are hanging and start reading, or pull out your cell phone and look at pictures. Anything, as long as you're not looking back at her and making her believe that what she's doing is making mom mad. It may take a while at first, but it may not. My son threw one tantrum, that's it. I remember it like it was yesterday. We were at the store, he was playing on the floor with a truck while i did some christmas shopping in the same aisle. When I told him to put the truck back so we could leave, he started screaming and threw himself down on the floor. I bent down and said, "Brayden, it's time to go, when you're finished, come find mommy". Then, I grabbed my cart and walked away slowly. While I stayed in site of him, I stopped here and there and grabbed something off a shelf to look at to keep my attention away from him. Once I got a certain distance, which was probably a good 20 feet or more from him, he stopped crying, stood up, and ran to me. When he came up to me I reached out my hands for him and lifted him into the cart like nothing ever happened. He never did it again. With my daughter, it was very similar, but with her she would want out of the grocery cart. So, I needed some practice other than in a grocery store. I took her to the mall (my kids are 15 months apart, so she was about 2 and then I had a baby with me), and everytime she started screaming about wanting out, I would head down a bathroom hallway and sit on the bench. I would pull out a book from my purse and pretend to read. As soon as she would stop for a second, I'd say "oh! You're ready to go now!" and put it away. If she started crying again, I'd sit back down. I taught her that if she's acting out, my response is going to be nothing. So, after some mall practice I went to the grocery store. When she'd start to cry I'd stop the cart and pull out my book. When she'd stop, I'd put it away and go. Before the end of the first grocery shopping trip, all I'd have to do is stop the cart, and she'd stop crying immediately. By the second week, if she started to act like she was going to cry, all I had to say was "we do not cry in stores", and she'd stop. If I were in your shoes, the second your kid started to cry, I'd say "okay, well mommy's leaving". I would talk to your daycare provider about this in the morning to give her a heads up. Then, I'd start to walk away, maybe pretend my cell phone rang so I had an excuse to stop at the door, and then if she was still crying, I'd walk outside and wait for her right outside the door. She WILL come out, especially if the daycare providers know to NOT pay attention to her behavior either. If you do this, I'd be willing to bet money that she won't do it again, and if she does, it wouldn't be more than once or twice, just for her to learn that mommy really isn't going to pay attention to her tantrums anymore