I have known gifted teens that meet all of the descriptors that you posted about your friend, except for the only child part. They were sisters. The manipulation skill was enhanced by their sensitivity to identifying others' buttons. For these two, it really boiled down to insecurity and perfectionism. They wanted to be perfect, to be loved, and so they lied and were defensive regarding anything that suggested to themselves or others that they weren't perfect. They manipulated others as a power play and as a way to show themselves that someone loved them. You can guess that the parenting wasn't great. IQ was never an issue in the household. The parents placed a high value on image, appearances, and competitiveness.
FWIW, one sister grew out of it and the other is doing very well in politics.
