In my head canon, the Miqo'te of D'aito Kuji's tribe, live on average 40 years. Â This is for all the reasons Sounsyy mentioned. Â Her tribe is traditional having changed little in generations. Â They are subsistent hunter-gatherers who have managed to survive in one of the most brutal areas of the Sagolii (conveniently located beyond the game map). But survival can be difficult. Â One bad season, dryer than normal conditions, or a sickness brought from merchants could cause a lot of damage.
On top of all that, members of D'aito's tribe are violent towards outsiders and this limits trade for critical things like medicine, potions, and spells.
Add to all of this the instability of the Nuhn, and it's easy to see why 40 might be a grand old age, and an age that only the females tend to see (it would take an exceptionally strong Nuhn to remain in that position much beyond 40).
Anyway, that's the really not the question that was asked but I really like to take Lore and add real-life-ish pressures to a group of people.
On top of all that, members of D'aito's tribe are violent towards outsiders and this limits trade for critical things like medicine, potions, and spells.
Add to all of this the instability of the Nuhn, and it's easy to see why 40 might be a grand old age, and an age that only the females tend to see (it would take an exceptionally strong Nuhn to remain in that position much beyond 40).
Anyway, that's the really not the question that was asked but I really like to take Lore and add real-life-ish pressures to a group of people.