Naia died young.

She was fifteen or sixteen, probably — old enough to be an adult in the context of a hunter-gatherer society that did not extend adolescence as long as modern industrialized societies do, but not old by any absolute standard.

She had not had children, as far as the evidence indicates — the skeletal evidence does not show the bone changes associated with childbirth.

She was, in the simplest terms, very young when she died.