It was fate.
It was the fate she and he had guarded for ten years. His destiny said, "When he is fifteen, he will meet the person he is meant to spend his life with, but he is destined to let her down for the rest of her life."
She wanted so badly to be the person in his destiny, but when they met, he was not yet fifteen. It seemed they had met too soon.
This is her story beyond fate, a story outside the bounds of destiny.