Throwing a feeler out there. Im in the market for my two children 8 & 10. Prefer 4 season and ultralight - but, at the same time best bang for the buck.
I just went through the same thing. There really isn't much in the way of dedicated children's bags. What I did was look at women's bags, and I ended up buying some from Marmot that were on sale, and in colors that weren't too "girly".