I expected that the goblin kids (at bear druid scene) will run away when the fight starts, and they did. Those goblin kids are evil, but would be difficult for them to be anything else in that entourage. Usually most games avoid the child killing. I remember killing demon kids in Nox (a Diablo like old RPG), but maybe they weren't kids, just smaller demons (they were red, attacked in groups and had funny sounds when exploded on death doing AoE damage, so was very different to BG3 goblins).
Child killing needs the option to be avoidable, which is in there so far. Rest is up to the players (some will do it, but most won't "enjoy" pointless kills)