So this is a little strange to say, but I'm not actually sure what to translate the 「えっ」 as. What does that mean in this context? Is she taking it as self-evident that she will be a vampire some day, and it's an affirmative, "Yeah[, I know. I won't be human though]"; or is it a truncated interrogative, "Really?" That the statements are identical and share a similar locality, I'm actually leaning toward the former, but the doubt is sufficient that I want to be sure.