It is only in Old Irish that we find the intimate forms being transferred to the foster parents.

In the Christian era, at least, divorce was not easy to come by..not impossible, but not easy. I suspect that death split up more families, foster parents and real parents, more often than for any other reason.

While, I'm sure the child would mourn the loss of the adult in question, I strongly suspect that they were able to accept what was all too often a fact of life.