Beans_on_a_tree
Bro. You are better off using an OC rather than choose a canon character. Other than Alice, the other female characters shown in twilight are meh. Even the attractive Denali's were basically sl*ts who literally invented the myths about succubi! So you are better off creating an OC character which will let you shape their looks, personality, and backstory however you want.
One of the Denali's for sure. none of the Cullen/Olympic coven are old enough, it's such a waste to have the MC just hiding away until canon starts. by the time anything important starts happening he's still just going to be some old nobody that none of the vampires have ever heard of or seen before.
I think you should make it all three Denali sisters after all none of them have a mate until a few years after the cannon begins, and even then only two of them find a mate and one of them is not even a true mate plus they’ve lived together so long I don’t think they really have that much of a problem sharing a mate