[She decides to offer a simple explanation first, and then answer whatever questions he might have.]
She is what some call a 'vampire', someone who feeds on the blood of others. She has an ability that allows her to turn others into vampires as well, even against their will.
[She hesitates for a moment, knowing that the next piece of information is probably not going to make him very fond of Conrad. But she has to tell him.] She has turned two people that I know, Ashton...and Conrad.