S.M.
D.,
The comment below was mean. But I do have to say that not everyone is created with the gift of rearing multiple ages and stages of children that are not related to us. I have been doing it for almost 25 years. And yet.. everyday is a new day full of ups and downs. My grandson is 19 months old and he's jealous of some of the other kids near his age. We only have one that's here most days and one that's here some nights. He has no issue with the older or younger children. You need to be patient, consistent, and creative. Sometimes it's a matter of distraction, sometimes you need to sit them down and have a talk and get them to open up about what's going on, and sometimes you need time out. The stage will pass in time :)
To one degree or another we go through this anytime a child leaves care for school or maybe they move or the parent leaves. Then we replace the child and the children here are both missing their friend that's gone and not yet ready to accept the new friend right off. It takes a little time to sort things out.