Bullying in School

I went to take Grace to daycare on Monday. She didn't want to go, it was crying and screaming that I not leave her. I knew something was wrong, but had a meeting that I had to go to. I feel so guilty for making her stay, but I assumed she was safe. That night when I had a conversation with her about day care she told me that, Jaylee is mean. She told me that she hits her and pushes here is "mad all time". It broke my heart. The next morning I went in and talked with the instructors about the issue, They were not aware of the situation and said they would watch. I had to go to another meeting, and when I returned I stayed down to observe. And I observed that Jaylee pushing, hitting, and being mean. In fact she hit Grace with a dinosaur for no reason. She was not held accountable so I quickly took Grace out and went one step up. After not feeling heard, today I went all the way to the director to discuss my concerns. "Mama Bear" was not happy. I have had many discussions with a lot of people and I hope the situation will be taken care of. The girl is only there part time so Grace is happy today, but I feel horrible that my little girl was being bullied. I feel like a terrible mother for making her stay even though I knew something was wrong (I just didn't know what). I told Grace, if she hits you, hit back. If she pushes you, push back, and if she is mean, be mean back (and then Grace said) "but Pie's Nice" Oh tear. What a little love. It was a good thing we had Dance that night to make our day just a little better. I just love this little girl so much!