I don't want to sound too mean and critical but I think these are some points you should be aware of and it will
help you improve.
There are some major proportion issues with this piece and I'll try to break it down as nicely as I can.
1. Their kids looks like their mini me or a smaller doll sized version of themselves. Children may be smaller than adults, but their head sizes are not that much smaller, the larger difference should be that a child's head is much bigger compared to its body than an adults. In your case, the kids would look like children if their head gets enlarged. Here's a guide on body proportions at different stages of life: http://fav.me/d41ivgd
2. Fllay and Kira's hands are much too small. The average hand should be slightly smaller than the face (test this out by putting your own hand to your face), while the hands here are about the size of their eyes.
3. Given the position they're in I think it's safe to place Fllay closer to Kira, since right now they don't seem as intimate and Kira's arm seems to be straight and only bent at his wrist, which would be quite awkward when the posture's acted out.
here are some other tutorials that may be helpful: http://fav.me/d5pmbmv http://fav.me/d547x43 http://fav.me/d5qb20q