I have been attempting to recall a particularly riveting young adult fantasy series that I had encountered many years ago. The series involves multiple young characters who each reside in different provinces, each province relates to a different element (There were four – fire, water, earth and air, if my memory doesn’t betray me)
From what I can recall, each character discovers their elemental powers in the first few books and goes on a quest to reach a secret sanctuary located in the central province, a place that harmoniously housed all four elements. In one of the books, there was also an adventure involving a particularly treacherous forest.
The most distinctive character that I can remember was a little girl blessed with water powers; she had sea-green eyes and her province was home to vivacious waterfalls and luminescent underwater creatures.
Any help would be supremely appreciated, I believe the series had a total of 7 to 9 books perhaps.
Could it be the 'Elemental Quartet' series by L.J. Williams? Fits your description quite well from what I can recall. The main characters hail from different provinces with distinct elements and the girl with water powers from a waterfall-dotted province rings a bell.