I suspect that Bella's problems trying to figure out how to control vampires would probably solve themselves once she removes the Volturi from power; if the vampires get out of hand, the human governments would notice, and they'd wind up bringing ever-escalating amounts of hardware to defeat them.
If she uses her father to make the appropriate connections with the US law enforcement agencies, she could probably make the transition from vampiric vigilantism to human law enforcement as smooth and painless as possible. He's a police chief; odds are that he knows how to contact the FBI, and they won't play around, especially once she demonstrates her vampiric superpowers.
I haven't stated this explicitly in the story, so that's fair enough, but I think an FBI that became aware of vampires would probably try to make them extinct, not tolerate the ones that are trying real hard now to quit the murder habit.
In the vein of the Harry Potter and the Methods of Rationality discussion threads this is the place to discuss anything relating to Alicorn's Twilight fanfic Luminosity. The fanfic is also archived on Alicorn's own website <strike>(warning: white text on black background)</strike>.
Previous discussion is hidden so deeply within the first Methods of Rationality thread that it's difficult to find even if you already know it exists.
Similar to how Eliezer's fanfic popularizes material from his sequences Alicorn is using the insights from her Luminosity sequence.
Spoilers for the fanfic itself as well as the original novels need and should not be hidden, but spoiler protection still applies for any other works of fiction, except for Harry Potter and the Methods of Rationality chapters more than a week old so we can freely discuss similarities and differences.
EDIT: Post-ginormous-spoiler discussion should go to the second thread. (If you have any doubt on whether you have reached the spoiler in question you have not.)