Leah Gibson has been confirmed via IMDB as Nettie for Twilight Saga:Eclipse (a Southern Vampire who worked with Maria and Lucy. She helped Maria attack Jasper (Maria is technically Jasper’s maker) along with their ’sister’ Lucy. The characters’ Maria, Nettie, and Lucy will be shown during Jasper’s flashback sequence when he explains to Bella his story.
In the books Nettie met the same end that Lucy did — they were killed by Jasper and Maria.
Nettie is described in the novel Eclipse as being very pale and blond.
Leah Gibson is a fairly unknown actress. She had a small role in The Watchmen. And is in a spin-off of the Sci Fi Channel’s Battlestar Galactica called Caprica.