Scarlet Moon

Scarlet Moon is a young vampire constantly parched by her mother, Violetta Moon. Violetta and Phineas, Scarlet's father, are the duke and duchess of Ethiontia, so they have many riches. Supposedly only Scarlets mother knows that Scarlet is a vampire but Scarlet's sister, Lavender Moon, eventually finds out.
Scarlet was bitten by two vampires by he names of Steel Terror and Azure Terror, the watch Scarlet grow up from the sidelines until they think she is ready to join the coven.
Scarlet's wooer, Alberon Black, is a vampire too. Scarlet's and Alberon's parents want them to get married but their vampire instincts tell them not to fall in love.
On Scarlet's 18th birthday Violetta presents Scarlet with a something to make her human again. There are three vampires against the idea. Scarlet turns down the offer and decides to stay a vampire forever. She also declines to join Azure and Steel so Alberon and she can make a coven of their own.