Valfred is given an official age of 69 years, btw.
If you're going by the official website, it also gives the hero and Liu official ages of 16, when it is stated pretty explicitly that the hero is 15. At the end of the game Rajim says that he was found in the valley 15 years ago, and we know that he fell through the gateway when he was a newborn. Also, Liu cannot be older than 15, as he ran away three years ago, before he was tatooed, which happens when at age twelve. Presumably he ran away at 11, though it could have been before, but I think he was 11 almost 12, making him 14 or 15 now. Also, according to the official website Chrodechild is a man. So that may not be the most sound source, though if you are getting your info elsewhere, I do not mean to discredit it.
Everyone loves Dragons. Cause If they don't.... >;(