A JW mom in my family did a similar thing.
The JW relative was getting a secular divorce, but needed proof that her JW soon-to-be-ex husband was cheating for a scriptual divorce. So, the JW relative and her female JW friend staged a date between the husband and a third, Non-JW Friend. The non-JW friend invited the JW husband back to her apartment. The JW relative and her JW friend sat in the laundry room, adjacent to the apartment. They couldn't get on top of the washer/dryers to be near the grate that led to the next door apartment, so they had the the 4 or 5 year old daughter "listen in" to the conversation/happenings in the apartment from the laundry room.
I don't think the little girl "got it" as to what was going on at the time or how sick it was all. But, now, I'm sure she does.
Just sick.
Skeeter