The Long Winded Journey to the Sun

Iris Rena never expected to be chosen for priestess until many years later, but when she is chosen when she is just 58 years old chaos seems to unravel. Most Sun Elves aren't chosen until 100, or well after. As the time goes by, Iris learns the mysterious goddess they worship may never have chosen her in the first place, all just a ploy of the council. She also discovers secrets within herself, things the goddess would kill her for, or curse her. A fate worse than death.

(I am awful at summarizing this, as it is spread over many years!)