There are two versions of this manip (and can I just say that Dawn fit like she was always meant to be there?); I couldn't decide which I liked better, and they both pertain to the semi bunny below. Check out the manips and the bunny and let me know what you think.
Takes place around the last season of Buffy and before the Twilight series. (I know I have said this before and I'm sure I'll say it again: I hate the Twilight books. The basic concept is nice though [somewhat Buffy like] and I can stand it when used in fics, usually because writers rewrite the books to suit their needs.)
The Vampy Trio took a different route on their way towards Forks. They decided to take a tour of the Hellmouth first. Different route, different fixation.
James becomes enthralled by a certain brunette (and we're not talking about Faith). Dawn follows in big sister's footsteps and finds herself just as enthralled ... though it might have something to do with curiosity of a new breed of vamp given the Watcher vibes Dawn starts putting out in the last season.
If anyone decides to write something like this, I would adore you if you made Victoria ... (how do I put this gently?) ... not insane. She and James are mated or whatever the vampy equivalent is in the Twi books. I think everyone goes a bit insane when we lose a loved one. Vamps are violent creatures and are likely to take this protective urge to the max, but is this really any different than what humans do? I mean, mothers and fathers have waited outside courtrooms with guns when a non-guilty verdict is reached in the case of their child's death, husbands have hunted down their wives' rapists and wives have murdered the town drunk after they killed their husbands in a hit and run.
That said, I'd like Victoria to be part of the decision to turn Dawn; James is like her husband after all. Maybe she likes Dawn; she would never say it of course, but she can pass it off as she's getting tired of doing all the work and the group needs another female, right?
Maybe the trio take Dawn when Xander 'kidnaps' her on Buffy's orders. Knock Xander out and no one will know she's missing until the Hellmouth closes. They'll just think Dawn and Xander are safe from the fighting.
The Vampy Trio + One are now free to continue on their meandering way to Forks. How will things be different with a newborn? Will James even become obsessed with Bella now that he has Dawn, especially with the new responsibility of keeping a newborn from going crazy on the populous and bringing the Volturi down on their heads? With no newborn army, who's to be the main protagonist? The Slayer army maybe, come to rescue Dawn with Buffy at their head? Take it where you will. :)