She's very cute! Yes, you have done an excellent job with her proportions, especially in her face. Her eyes, ears, nose and even her buns are extremely well balanced. You've also done an excellent job on her hands. I'm very impressed with them!

Her arms and breasts are a little off. The arms are off only because they are far too skinny along the top, near where the armpit would be. Generally, in anime style, it is perfectly acceptable to make the line of the breast curve up into and be the same as the shoulder/armpit line. So by moving that line that you currently have over to merge with the breast line, the arms will loose most of their extreme skinniness and look more full, the way a healthy young girl like her should look!

I really love her design. The way her hair curves softly around her face is very cute, and accentuated perfectly by those little buns. I would love to see an inked and colored version of this picture!