Hurt

This isn't about me, or is it?
I can't always protect them. Even when I should have been there, I am not always. It hurts more than the incident, my guilt and frustration. I hope they have forgotten because I can't get over it.
A boy bit R yesterday. We were at our weekly meeting with other moms and kids. I was sitting outside talking. R crawled inside. I got up to see what she was up to. A boy was next to her; he is almost three. He bent over. I thought he was going to kiss her. Then she started screaming. I understood he had bit her. I ran over, yelling at the boy. I picked up my baby. Red ugly welts beginning to form on her back. My baby. The one who is still innocent and sweet, not old enough to hurt anyone. And out of the blue such pain, for no reason.
I started crying with her. Angry tears of frustration for not having been near her to prevent this. Hateful tears, at this little boy who hurts for no reason those who cannot protect themself. Tears of desperation because I can't always be there to guard them. Tears of guilt because I should have been there.
And the boy's mother, you are asking. What did she do? She yelled at him. She reprimanded, explained, apologized. It doesn't make it better, though. At least not for me or R. She even called me twice to see how R is. R is scared. She doesn't want to be near other children anymore. Kids come near her and she starts crying. I am doing something wrong. I need to stay near her until she is older and can protect herself. I feel horrible.