As in your first illustration, I think it will help you alot to have a reference image you can refer to, to help you keep your character consistent…time to snag another photo of your little brother! 
I took a quick look at the new image of your character, and it looks like you’ve aged the boy a bit and added some feminine qualities to his features. Take a look at his left cheek and you can see that you’ve increased the curvature inward where in a younger person that is still quite rounded. Also, you’ve raised the hairline a bit, I think. Also, the nose and eye area…as in your first image, you’re having a bit of a problem there…you’ve narrowed the nose this time and made the tip a bit narrower…again aging your character by doing so.
I hope you don’t mind, but I did a quick sketch of your character to show what I mean…sorta. It’s not quite at the angle and turn that you have in the new image, but I was trying to understand the differences in your first one as compared to the second and it helps if I sketch it out myself as well. Anyways, hope that gives you some ideas. 