Existe uma idade máxima conhecida para os filhos da floresta? Eles podem se reproduzir?

Livros

Não, não sabemos a idade máxima dos Filhos da Floresta.

Conhecemos o tempo de vida de pelo menos um Filho da Floresta que podemos usar como ponto de referência:

Meera said, "You speak the Common Tongue now."

"For him. The Bran boy. I was born in the time of the dragon, and for two hundred years I walked the world of men, to watch and listen and learn. I might be walking still, but my legs were sore and my heart was weary, so I turned my feet for home."

"Two hundred years?" said Meera.

The child smiled. "Men, they are the children."
_{ADWD - BRAN II}

Desde que ela diz que nasceu quando Dragons governou e viveu pelo menos durante séculos 2, isso fará com que sua data de nascimento no reinado do rei Jaehaerys I. E escusado será dizer que agora sabemos que pelo menos alguns deles podem viver até os séculos 2 e talvez mais, considerando o quão saudável e jovem Leaf parecia naquele tempo. Ou podemos simplesmente dizer que o tempo de vida deles é muito maior que o nosso e deixar por isso mesmo.

Quanto à reprodução, sim, eles certamente podem, embora em um ritmo mais lento que os humanos. Eles simplesmente não saem do chão. Na Era do Amanhecer, viviam apenas as raças anciãs de Westeros, que eram as Crianças e os Gigantes. Eventualmente, os Primeiros Homens começaram a chegar da ponte de terra que ligava Westeros a Essos. E com essa migração, vieram as guerras entre as crianças e os Primeiros homens. Com a maré virando-se contra eles, as crianças se voltaram para armas desesperadas e usaram a magia para esmagar a ponte terrestre que ligava os dois continentes, chamada Braço de Dorne. Mas era muito pouco e tarde demais, já que Milhares de Primeiros Homens já estavam em Westeros e, mais importante, Esposas dos Primeiros Homens tiveram filhos mais rapidamente do que as mulheres das raças Elder, que distorceram ainda mais a balança em favor dos homens até que os filhos fossem. forçados a perceber que eles não poderiam vencer esta guerra.

Most of what we do believe of the Breaking comes to us through song and legend. The First Men crossed from Essos to Westeros by land, all agree, walking or riding across through the hills and forest of the great land bridge that connected the two continents in the Dawn Age. Dorne was the first land that they entered, but few remained, as we have chronicled; many and more pressed on northward, through the mountains and mayhaps across the salt marshes that once existed where the Sea of Dorne is now. As the centuries passed, they came in everincreasing numbers, claiming the stormlands and the Reach and the riverlands for their own, eventually reaching even the Vale and the North. They drove the elder races before them, slaughtering giants wherever they found them, hewing down weirwood trees with their bronze axes, making bloody war against the children of the forest.

The children fought back as best they could, but the First Men were larger and stronger. Riding their horses, clad and armed in bronze, the First Men overwhelmed the elder race wherever they met, for the weapons of the children were made of bone and wood and dragonglass. Finally, driven by desperation, the little people turned to sorcery and beseeched their greenseers to stem the tide of these invaders.

[.....]

Most scholars do agree that Essos and Westeros were once joined; a thousand tales and runic records tell of the crossing of the First Men. Today the seas divide them, so plainly some version of the event the Dornish call the Breaking must have occurred. Did it happen in the space of a single day, however, as the songs would have it? Was it the work of the children of the forest and the sorcery of their greenseers? These things are less certain.

[....]

No more wanderers crossed to Westeros after the Breaking, it is true, for the First Men were no seafarers...but so many of their forebears had already made the crossing that they outnumbered the dwindling elder races almost three to one by the time the lands were severed, and that disparity only grew in the centuries that followed, for the women of the First Men brought forth sons and daughters with much greater frequency than the females of the elder races. And thus the children and the giants faded, whilst the race of men spread and multiplied and claimed the fields and forests for their own, raising villages and forts and kingdoms.
_{TWOIAF - Dorne: The Breaking}