Okay, there are two separate issues going on here and I'm playing catch-up!
Dar, I am sorry about your daughter and I know how you feel firsthand. It is sickening. Please emphasize that your daughter has done the right thing and that she is not in any way to blame. Additionally, this amounts to sexual harrasment in the way that you describe it. That other child should be in counseling. What may or may not have happened to HER is not your problem. There are psychological tests that can be administered to a child that will reveal the any abuse she herself may have suffered. I know because when my daughter was 10, she had to take them. Insist the other child's guardians take action now or someone else is going to suffer later.
Your husband: Leave him alone and hush your mouth.