The page of drawings above didn't feel quite right. The two at the bottom were better, but he looked too old. Little Brother should just past the toddler stage, where a kid is talking and walking and mobile enough to be trouble, but not old enough for school. Preschool maybe. We often say he's two but I think he's a bit older.
The basic head shape.
Look what a great match that is for the design on the second page of sketches.