Sands, Lynsay. Argeneau series

A simple promise to protect her friend's infant son has turned Allie Chambers' existence upside down. Caring for--and feeding--an orphaned vampire baby has been tricky. When her attempts to steal from a blood bank go awry, Allie wakes up surrounded by doctors, cops . . . and the gorgeous, mesmerizing Magnus, who she can neither trust nor resist. Magnus never expected to find his life mate breaking into a blood bank. Clearly, Allie is already entwined with his world--in deeper, more dangerous ways than she realizes. A band of vicious rogue immortals is in pursuit, and Magnus' first task is to keep her safe. His second: to awaken her to mind-blowing pleasure, and hope she'll accept the life, and the passion, that only he can offer