Hi MM,
Well I do have a kinda similar story. Very early I forget exactly how early my DS would draw faces w/eyes nose mouth, I remember a friend who had a DD same age being amazed at this. Anyway, my DS6 now, is the WORST drawer still drawing stick figures, hates hates hates to draw. Now, the other DD is an AMAZING drawer NOW. So it is interesting.
My DS6 therapist says it is not his thing, and he doesn't like maybe because he can't do it perfect.
So yeah it was odd my DS drew w/detail very early and now years later still draws stick figures.