What would you have done, in Buffy's place?

[Cherchezlafemme]

Am I wrong for wanting Buffy to have pushed Dawn into the portal? Mostly because she irritated me, but honestly, because the whole "the monk's made you out of me" thing was weird: how was Dawn made from Buffy's DNA if she wasn't real? If magic permits substituted sacrifices, then what is the point of a sacrifice? And for that matter, how did Buffy's body end up on the ground if she jumped into a portal!?