>>95557853Standard doppleganger situation. Pull your mirror out of your pocket and begin to invoke En Var. Do not finish the invocation, En Var would actually just make this situation worse, but the doppleganger will panic at the name of the patron god of its eternal enemy, and that's how you identify which one is the real child. Dispatch the doppleganger as normal.
If both of them panic, this is a lose/lose scenario where both of them are dopplegangers and your kid has already been abducted to beyond the boundary. In which case dispatch both dopplegangers as normal and prepare for a hedge dive.