If manipulation is a problem, I highly recommend the book "The Manipulative Child," which I think I've probably mentioned before. It's very eye-opening just in terms of being able to RECOGNIZE and face those situations in which our kids are deliberately (if pleasantly/passively) manipulative.
My DD is another Zen Master at manipulation. It's as natural to her as breathing, and we've done a lot of hard, hard work to make her more self-aware and give her other options for managing her need for control/autonomy, encouraging more direct/assertive communication, etc. Unfortunately, the world conspires to lead very bright girls down that path of becoming manipulative, because it's how they tend to get the best results with most situations; cheerful covert manipulation over assertive problem solving. It's part and parcel of what they learn as HG+ females, unfortunately. Nobody takes them seriously enough to listen to them, so they resort to other means.
What is scary is that they KNOW that they are just children in some ways-- so the ability to manipulate/coerce/persuade adults against those adults' natural inclinations is pretty frightening stuff. DD never respects an adult that she can manipulate-- this was a HUGE problem when she was much younger. Probably this peaked about age 6.
We worked at developing compassion alongside theory of mind, and emphasized that other human beings have the same rights to autonomy and control-- ergo, it's WRONG to use passive-aggressive methods, even if it's easy/possible.
