I made this in TesVsnip, and it allows you to have children be mortal like any other generic adult npc in the game. There are a couple essential children, i only tracked down 3 so far, if you see any more post there names in the comment box thingy.
Installation instructions:
Unzip the .esp to C:\program files (x86)\steam\steamapps\common\fallout 4\Data
Open a File Explorer Window, go to %LocalAppData%\Fallout4\plugins.txt and add Killable Children.esp to the bottom of the list.
After you put the esp name in the plugin.txt remember to right click it and set it to read only.
