I know you've considered it done, but since you posted it just today, I'll just fire away nevertheless.
Firstly, can we see the photographic reference you've used, so we can offer proper critiques?
I think her neck is a bit wide, but that could be just your interpretation of the light. Also on her neck, there're 2 lighter spots that seem out of place.
Another thing: your dither is making way too noisy transitions, for that much skin colours.
Maybe these things are contributing to the issue:
1. On the top circle, a colour darker than colour 1 is touching colour 2, creating cleared borders between pixels.
2. The transition between colour 1 and 2 could be less drastic. On the other hand, the contrast between colour 2 and the darker tone is quite bland. Lightening colour 2 could be the solution.
3. Try to study more dithering patterns, so you'll have enough tools to make transitions smoothly when things get rough. For instance:

Anyway, I hope your friend enjoys her gift!