Welcome to Gaia! ::

Problems I see are sloppy coloring (esp. in the hair) and linework. Clean up your lines so that they are crisp and not choppy. Also, in the eye there is no shading to define that the eye is round or inside of the head, it looks like it's just stuck on. To change this you could study a real eye, look inside of the white part. It's not completely white! Your eyelids make shadows on the eyes. Maybe use a different color (a muted brown or deep red) to use for the lines of the lips. The black is a bit overpowering especially where you define the upper lip and bottom lip. I like how you did the nose but the little dot you used for the nostril doesn't convince me that it's a nostril. Try defining that a little more. Also, with your lines try to end them a bit cleaner (like on the neck, maybe extend that line a bit more so it doesn't end so quickly). Add more shading to the actual pupil of the eye and concentrate on your light source more.

It's cute but I feel like it's still a work in progress ~