Oh boy Lou, it sounds like you have it all under control and are absolutely doing the right thing. I only had one child like that and I said about 100 times a day - don't tell me, talk to your friends. It was exhausting to have that child around and you have 2? Oh, I feel so bad for you!
I asked her Mom if she did it at home and the Mom said she even tattled on the cat. So I got the parents on board to say the same things I was saying. I think it helped a little. But I mentioned to the parents that dcgirl's personality was forming and they didn't want her to be like that when she got to school, did they? I think appealing to the parents that way helped a bit. Good luck to you!