In Chapter 16, what does Rose tell Lissa about her powers, and how does Lissa respond?

Rose tells Lissa about Vladimir's healing making him crazy and ill and depressed. She feels that this is probably the cause of Lissa's cutting, since it started right after Lissa healed the raven. Lissa thinks that this is crazy. Rose asks Lissa to stop trying to be part of the royal clique, but Lissa refuses to stop, offering to stop using her powers instead.