Potty training - Day 3

We're part way through Day 3, and I have to say that today is going extremely well. She peed in her diaper before I went into get her this morning, and she told me that outright. I dressed her and off we went to her sitter's. She had a glass of milk around 9:10, and within an hour or so, the sitter knew that Makayla was holding her pee based on her stance (knees twisted inward). She would keep asking if Makayla had to go pee, but she would say no. At around 11, the sitter explained that sometimes your tummy hurts and so when you pee, it won't hurt anymore. Shortly after that explanation, Makayla said she had to pee. Away they went to the bathroom and then she asked "Can you hear it?" They had a big hooray with all the kids and called me to let me know of her success. By 3pm, I had received 2 more phone calls. One about a poop in the toilet and one more about peeing. Each time Makayla had told the sitter she had to go. She is still wearing the same pants that I dropped her off in this morning! I had been so focused on finding what incentive would work for Makayla, that I think I overlooked the obvious...she didn't know what I meant went I asked her if she had the "feeling" that she had to pee. She didn't know what the "feeling" felt like. After the sitter's explanation of her tummy hurting, I think she is putting it together.