Looks good. You have the best, and most difficult, perspective since you know the person. The way you think of her affects your rendering, and makes you more critical of the final pattern.
The major features of the image are her beautiful eyes - yo have done a fine job there.
Hair is always difficult to get right. With fine, light colored hair like I see here, less detail (fewer, thinner lines) is usually better.
Don't try to capture every line in the face. It's better to let the imagination fill in some lines.
I attached a rendering for comparison - not better, just a little different and for comparison.