Chaldene was born, rather untraditionally for her kind, to her mother. She was the result of a fun summertime fling between Cyllene and Sun Chaser, a stallion whom she has never yet met. Her mother, being a bit useless at responsibility, didn't really know what to do. Chaldene was raised to believe the world is a place of fun and adventure, everything in it is a game or a challenge. She grew up without a care, and barely knows how to look after herself. The words "safety" and "caution" won't ring any bells. Her mother lived for the moment, and Chaldene was dragged along after her.
It was a fun, if danger-prone, childhood. Now she's grown up she's started to explore the world up above, as she grew up entirely in the ocean. It really is one great big adventure for her.