Wow, that's really rude of her to hit your child with her cart! I am also curious what she said when you called her the name?
Well, let's say maybe you could've handled it better, by not calling names, but are you sure she intentionally did it, or was it just an accident? Maybe she didn't see your child, or maybe i need to re read your post, lol. Did she apologise? You know, sometimes I feel that we are no better if we call someone a name. I know you look back and feel as though you could've handled it better, so it may do no good for me to even say that, since you already know. I hope this isn't taken wrong. Maybe you could've said something like, "Excuse me Ms., what do you THINK you're doing, you just hit my child with your cart! Or something to that effect. That way you don't come off looking just as bad as the woman who hit your child with her cart. Ok, you weren't nearly as bad as her, but you get what I'm trying to say.
I am so sorry your child was hit. I can't believe how rude some people are!!