From her introduction Elissa appeared to be quite cold (for modern sensibilities). She talks in profits, gains, and losses. So much so that she appears a lot colder than her father Hanno, who is willing to bet the future on the orphaned son of his old friend, regardless of losses. Elissa on the other hand, once the calculation all checks out, very willingly agrees to marry herself to Hamil the cement the alliance between Hispania and Qart Hadast. Even during the encounter with slavers she decided whether or not to resist not by fear, confidence, ability, or really the situation, but by calculation of gains and losses. So when Daphnis decides to pull a Heroic Sacrifice in order to give her a chance to escape, completely in line with his position as a bodyguard and a slave, she appears to try to brush it off as a return on investment for his purchase when they were young. But she quickly stood up and interrupted the entire thing, even when it meant (as far as she knew) certain death. She proceeds with a Anguished Declaration of Love and states she'd rather they die together.