Hmmm.
This a very sensitive matter and it's so hurtful.
I had to go read Hive account@sirknight's post to fully understand.

So,

1. I'll get my child away from that surrounding immediately. This may mean moving out of my house for a few days.
2. I'll get a Lawyer and a private Detective involved
3. I'll get my child medical attention. Physical and psychological treatment.
4. I'll get the police involved.
   I don't care if it's my spouse that's involved or my mother sef. The investigation will be taken care of by detectives.
   *I'll make sure the offender is treated for the crimes as the criminal that he/she is.

Lastly, how to know these stuff.
Well, for starters, I'll be plain with my kids.
Penis is penis, not bumbum
Vagina is vagina not bumbum.
I'll let them know about what sex is and how it's inappropriate for anyone to touch them on places in certain ways.
I'll be very free and open with my kids, it's much better than the closeup method used in the past.
I'll also be attentive and sensitive to notice any foreign recline. Once any of my kids gets more into his/herself, my red light will come on.

So Help Me God