Monster children have been in D&D a long time. You'll find mention of goblin and hobgoblin children in the AD&D Monster Manual and B1 Keep on the Borderlands, for example. In all those D&D cases, the monster children are non-combative, yield no treasure, and convey no experience points. Sort of like squirrels. Regardless of whatever alignment I play, I do not derive any game satisfaction from racking up squirrels.