Au where hollyleaf is shadowsight's guardian angel kinda thing-
Its where hollyleaf is left to be a wandering ghost until she fulfills a destiny which lets her into starclan. When the whole ashfur/bramblestar thing happens, she takes shadowsight under her wing, sympathising with him with the fact that ashfur both ruined their lives and led them to lashing out at others.
She protects him from ashfur in the battle in the dark forest, and is allowed into starclan :]

(Oh yeah she has 6 eyes and 4 ears for funsies!)