I think mothers, and fathers, loved children as much or little back then as they do now. That being said, I do belivethat if something like loosing a child is bsaically a daily occurance, shared with family and friends, makes it easier to cope with it. Even if it is just by maybe getting a little numb.

As far as PTSD is concerned, I remember a commentary / documentation (I suck at keeping my sources, so...) that went a long these lines:

- War was more common, when everybody is kind of traumatized, society copes with it better - soldiers were traumatized, but it seems less so when compared to modern war, which brings me to the last point: - the most horrible war experience back then was battles (sieges, field battles,...), off battle, life for the soldier was as dangerous as a civilian's one. In modern war, the soldiers stress was constant, everywhere and the enemy (artillery, snipers, air craft,...) often invisible, increasing the stress levels a lot

I am no expert in psychology, but it does sound logical.