What I didn't say earlier is that my HG+ middle child is going to grow up to turn into HKs DD as far as willfullness goes. When she was 2yrs old and I decided she was going to nap IN her cot and I was NOT going to rock her anymore (I sat down next to her and talked calmly to her) she sat down next to me in the cot and screamed at me for the full 2hrs until nap time was over, got up and went on with her day and then did not nap again for TWO WEEKS. I did not try that approach again.

When we had her assessed by a psychologist for selective mutism at barely 5 I was told, rather cheerfully "Do not go head to head with this child, you WILL lose. She's not seeking conflict, but if it arises she WILL see it to the bitter end, so pick your battles and go at her sidewise." Tell me something I don't know...