Board Thread:False Info and Speculative Discussion/@comment-4148963-20141013011052/@comment-25176701-20141013200119

I don't think there is an age limit because The Hales are born werewolves, so they were werewolves from the moment they were born. And anybody can be bitten by an Alpha and become a werewolf if the bite takes. It was just mentioned in the series that teenagers have a better chance of having the bite take effect.

However, for born wolves I do think there is an age where they start to transform. Born werewolves are werewolves for their whole lives but obviously a baby or toddler wouldn't be able to shift into a werewolf. I'm guessing around 12/13 they start to shift into werewolves. But for bitten werewolves I think that they can shift without being a certain age. They would just shift the next full moon. The bite probably wouldn't take effect and turn them if they were a toddler or young child, though.