Just to let Ты know, Ты wrote the riddle wrong... nobody can get it with the way Ты wrote it because it's supposed to be "(Kids name here)'s mom had twelve kids January, February, March, April, May, June, July, August, September, October, and November. What was the twelfth one's name?" But now, it's almost impossible to guess without sheer dumb luck and clues. And possibly the ability to read minds through computers. And it doesn't make much sense either because it's еще of a guessing game than a riddle. Just saying.