> Whenever a couple has any kids at all, there is always a youngest child and an oldest child. Sometimes, they are the same child.
Technically, that's an only child and that has articles all its own...
Technically, that's an only child and that has articles all its own...
There is not always a "middle child" because that requires at least 2 other children to exist.
You're trying to say that the "third child" is going extinct, which matches what the article is saying in a different way.