Great acting and a good plot.

Spoiler from hereon, ending explained.

Scene A: Child Wife controlled child husband.
Scene B: Mom told Wife that it was her plan all along.

= Child Wife and Mom schemed everything, and Child Wife told Mom she has to erase her own memories so their plan will work. Once the plan comes to fruition, she will regain the memories.

Scene 3: Child number 11 was controlled by the child wife to do exactly, well, the plan.

Conclusion: Since they were kids, child wife controlled everything.

a. Child husband cutting the ear of Number 11. Both guys were already under her control, they were testing how long her control could stay intact.
b. Her husband's father was no doubt under her control as well. This way, after the child's wife erases her memories, the "escape plan" will work without a hitch.
c. The rest is history.

Goal, or rather goals:
1. Create a real family bond. It's the reverse of terrorism and secret agent trainings where cells only have a fake family bond. Their plan was to create a real bond that no one can ever find a loophole. In other words, the perfect [sleeping] cell and operatives.
2. Teach them self-control. A wild agent is useless if they don't learn self-control. All of them need it, including the two kids. Noticed how it always revolved around self-control?
3. Test the wife's power. Her power isn't only about creating a false memory/experience, it's mind control. Can the victims resist? Her husband did not. Number 11 did not. Her self-mind control also worked so well.
4. Train the kids. They are far stronger than her and her husband, and thus far more dangerous if they don't have a family bond. This was proven with the female twin. Without a family bond, she was a ticking bomb.
5. Prove that the wife's plan "Family Matters" is actually worth it. Which, by now, we know it was worth it.

😉