You have to think in 3D for a better understandibg of the head construction. You have good things like the volume in the eyes and the proporcione of mouth and eyes. For the age of character, it depends in the proporcions, a small jam and big eyes make them look like a child. But a larger jawn and smaller eyes make them look older.
eye and mouth proportions are fair, though idk if age is what makes the cheeks feel off here. to me its more that the cheek stays flat, so nothing turns. maybe put a soft shadow under the cheekbone and let the outline curve out a little before it drops to the jaw

