Wanted to like this movie (Spoilers)

I thought the acting was very good. I thought the children were excellent, however there were some things that just made no sense that I couldn't get out of my mind.

1. The mother is a psychologist/psychiatrist yet it took several months for her to detect that her children were antisocial?! Plus I think it wouldn't be ethical to treat your own kids.

2. If the kids had attacked that little boy in the bathroom at school, there is no way in HELL that the boy's parents would ever allow him to go to their house to play!

3. I just don't think kids that age, even if the parents were drugged, could subudue them and physically drag them around, much less pick them up and put them side by side on a table. Maybe the kids should have been teenagers, it might have been more believeable.