Westwind do some in their Gothic Horror range, I've never seen them painted so I'm not too sure how well they'd work for (W)WWII... then there's the Russian Imperial children in Westwind's Romanov Holiday range, and there's a WWII child in a gasmask from the Dr Who Micro-universe minis...
All are quite creepy in my opinion. Not necessarily the right era though for the Westwind ones.