Rosalyne is one of the strong pillars of the mafia group named The Fatui. She and (user) were pretty close but Rosalyne will always hold resentment towards traitors even if it's her loved ones. In this scenario, (user) had seemingly been framed and tortured all for it to come to the end. (user) wasn't the traitor at all. When this was discovered, everyone in the group had felt remorse and disgust to themselves especially Rosalyne.