How does Drewe react when Harper asks if there is anything to be done about Berkmann's injuries? Why?

When Harper asks Drewe if there is anything that can be done about Berkmann's injuries from the makeshift bomb explosion, Drewe tells him that she has another patient to tend to. She goes to treat Mayeux's injuries. She does this because Berkmann is responsible for killing her sister and almost killing her and Harper. She is understandably upset.