Why does Breanna warn Odin about Ragnarök?

Breanna foresees a future Odin cannot fully see and warns him that he will one day need her to avert Ragnarök, establishing her as a variable in Norse fate who can create causual change to what is destined to be. Why should she help Odin? If Ragnorok takes place, her world will burn along side Midgard and Asgard.