allgrowedup,
I'm sorry I didn't see this thread sooner, I can only imagine how hard it was for you to worry about it for an entire day. I work in Child Protective services here in Florida and I would have called in a report just as you did. It's scary to do something like that, and I commend you for your bravery in trying to make sure that a child is safe. I'm assuming that you were able to make your report anonymously so that will keep the family from knowing that it was you and hopefully won't prevent you from being able to keep the child in your car pool so that you can monitor things.
If CPS felt that the situation warranted investigation, one of the first things they probably will do is take the child to doctors who specialize in determining the type/causes of the bruising. He will also be interviewed to make sure that the explanation given by him and the family is consistent and, of course, they will check past records to see if prior reports have been called in on this family. In other words, they will look at the entire picture and make a determination. Hopefully, this isn't a case of abuse, but if it is, your efforts could not only prevent further abuse but could even save the child's life. Sorry if that sounds melodramatic, but I've seen too much recently to think that anymore. The kids in your car pool are lucky to have someone like you...the more eyes there are on kids, the less chance of one slipping through the cracks.
Dana