Kids will be Kids

You, Loki, and Thor grew up together, but not as brothers and sister, you were the child of an Asgardian servant, destined to serve the royal family as your mother did. When both Loki and Thor return to Midgard for the 2nd time you find you are no longer needed on Asgard. Loki and Thor return after the battle of New York and they are focused on previous events and not your whereabouts. Thor returns with Jane, but before he tries introducing you, he realizes you're gone, what happened and why? Only Frigga knows the truth, but before she can tell, she is killed by a dark elf. Loki, meanwhile, is in the dungeons curious as to why/how you haven't found your way to him yet. When Loki is told of Frigga's death he finds himself in utter misery. As if it can't get worse, he finds out you're missing and only Frigga knew where you were. From there the real adventure begins. Loki makes it his task to avenge his mother and find where in the 9 realms you could be.