She witnesses his confrontation with Suzaku and learns about his true identity, the truth about the massacre of SAZ, and his Geass power. She flees in shock rather than helping Lelouch to deal with Suzaku, and goes into hiding.
As a result, she witnesses Suzaku's clash with Lelouch and learns about his true nature, the circumstances of the SAZ slaughter, and his Geass powers. Overwhelmed, she flees instead of aiding Lelouch in confronting Suzaku, and goes into hiding.