Eve knew it was risky to reveal the entire truth about herself to Rosetta. The leverage they had was that the vampiress was deeply in love with Eugene, and it was Eve, who in the end, had helped revive Eugene back through the vampiress's blood. She also hoped the friendship she shared with the vampiress would help the young woman from telling it to anyone.
As Eve watched an unconscious Rosetta, she heard Eugene ask her, "Miss Eve, Is everything really alright? You seem tense."
Having been around and taking care of Eve for so many years now, since the time Lady Aubrey and he had taken Eve to the Dawson's house that night they had found Eve for the first time, Eugene could easily tell when something worried her.
After a lot of thought, and with Rosetta still unconscious, Eve whispered, "I know who stabbed you," gaining Eugene as well as Timotei's entire attention, who had been pawing at Rosetta's face to check if she was really unconscious.
