If you “lose a child” of a couple on which you are working, don’t assume the child died? It’s possible that he went to live with a relative or even a stranger if the family had too many mouths to feed or if the relative needed extra help on the farm or with the household chores and young children.
It was not unheard of to “farm out” children to others–and this applies to farming and non-farming ancestors.
If the child disappeared, consider that she could be living with other relatives. If that relative lived a distance away, the child may have ended up settling in that area.