Through the Looking Glass, Darkly

With the war between muggles and magicals going on for years and with no way to stop it, Arya Potter decides that the only solution is for her to go to another world and prevent it from happening. (In which FemHarry from another world raises Harry Potter, helps him destroy Voldemort and save all the people she saw dying). FemHP/SS, maybe threesome with LM. Maybe Harry/Draco.