Now then. I think this is a very sweet image but there are some things I feel could be improved upon and I've tried to highlight them in my "line over".
1) You tend to put quite a mop of hair on your girls... Remember that the eyes are approximately in the middle of the tip of the chin and the top of the head. Then of course there may be plenty of thick hair on top of the scalp, but usually the hair isn't all that fluffy on top since gravity pulls it down. So I suggest a bit of a downsize.
2) Her neck is very wide at the top and then slims down, I suggest making it more delicate at the top as well.
3) With your current shading - which I understand isn't final - you've really emphasized the roundness of her shoulders. You've also emphasized it with the shape of her arms. I think maybe you'll want to make the arms a little straighter (unless you want a symbolic "heart shape" to be created by the shoulders for extra sweetness!) and I also think you should add a hint of armpits (well, the edge between arms and torso).
and 4) which I honestly wouldn't have noticed if Dave didn't point it out, but yes the wrists of her hands and her arms don't seem to be in the same place... I'm not sure how to explain it well, but if you draw the lower arms as their own oval shapes (or stumps) without hands, and then add the hands, the edge of the palm of the hand would be in about the same place as the edge of the stump (assuming you didn't make the stump too short
), so basically her hands should be placed a bit lower. Their inner structure looks fine to me, though