Peter and Charlotte

Peter and Charlotte are a pair of nomadic vampires who wander the United States.

Peter
Peter was a newborn recruited by Maria into her army of newborn vampires. His kindred spirit and combat skills appealed to Maria's second-in-command, Jasper Hale so much that he convinced Maria to keep him in the army.

Charlotte
Charlotte was a human girl who was in the wrong place at the wrong time when Maria went to recruit new members.

History
The two first met when Charlotte was brought into the Mexican Coven. They grew fond of each other over time, but as Charlotte's time came closer, Peter became increasingly worried. When Jasper was about to execute her, Peter urged her to run and then ran with her. While on the run, they both cautioned for any following pursuers, until they realized that they weren't being followed.

By escaping and moving to the northern United States, the two find a new and more peaceful life together.

Breaking Dawn
Jasper and Alice locate Peter and Charlotte and persuade them to go to Forks to help their adopted family testify against the Volturi.