The story of Mary Alice Brandon (Alice/Bella)
25 parts Complete Mary Alice Brandon stops the murder of her mother, but is sent to the insane Asylum anyway for confronting her father about the affair he was having behind her mother's back. We follow her life from the time she was bitten by her maker to the present time in Twilight, where she meets Bella, a really interesting human girl, that she saw before, in a vision over 50 years ago.
There's some major canon divergence but this is always how I imagined the story playing out. The only canon couples I left in this story are Rosalie/Emmett and Carlisle/Esme.
Best ranking: #20 in lesbian
# 970 in twilight
70'000 - 75'000 words