Daylight's Crown Series by Ripley Proserpina

A river of poison runs through Rose's veins. Ten years ago, Rose Carrado, a fragile child who made the mistake of trying to catch snowflakes, nearly died on a dark winter night when terrible creatures of legend overran Boston. Rose was easy prey. As she lay bleeding—dying—she came face-to-face with an ancient being, one who commanded her to live.  So she did.  Now a young woman, Rose lives with the consequences of that command... moreA river of poison runs through Rose's veins. Ten years ago, Rose Carrado, a fragile child who made the mistake of trying to catch snowflakes, nearly died on a dark winter night when terrible creatures of legend overran Boston. Rose was easy prey. As she lay bleeding—dying—she came face-to-face with an ancient being, one who commanded her to live.  So she did.  Now a young woman, Rose lives with the consequences of that command. Changed forever by the creature who bit her, she is a reminder of a time humans want to forget.  But she also possesses something else—a connection to those ancient vampires who saved her life. When brothers Ra, Seti, and Horus return to Boston, the ties binding them to Rose snap tight. For the first time, they encounter someone who has the power to throw their unending existence into the best sort of chaos and they will not allow anything—not life, not death—to take her from them. less

She's already cheated death once...Rose's hometown is a war zone. A madman holds Boston in his clutches, using an army of ravenous immortals to take what he wants.Only Rose, Horus, Seti, and Ra stand between annihilation and survival. So, while the vampire brothers had sworn they wouldn't fight again, they'll do what they must to protect the woman they love.But Rose has changed. She's ready to charge head first into battle, and more than willing to lay waste to anyone who threatens her vampires.