I've had a terrible time getting children to eat stews, Just like real ones! You CAN do it but as mentioned, you have to fiddle with them and drop several times to get the right spot. If you've got a lot of villagers milling around it is even tougher to get them in the right zone. When I have a weakened child and can't get them onto the stew, I feed them at the food bin instead. That always helps if you have food.
Tess