Because she would do that for anyone.

Arwen had long known the situation had already slipped off her hand. She wanted to leave quietly earlier. But given all that Gianna has said, there is no way Ryan would let them leave this place in peace.

Delyth's face, on the other hand, turned red the moment she heard Gianna put her words that way. It was a blatant insult. She tried to retort, to defend herself, but Ryan beat her in it. 

He spoke instead, "Gianna, you are misinterpreting the things. Arwen was here when Delyth was about to fall off the stairs, I was just —" 

"Misinterpreting?" Gianna asked, raising her brow in quiet amusement. "I think it's not me misinterpreting anything here, rather you are misappropriately presenting the things. Or wait a second," she paused briefly before adding, "Not just misappropriately presenting, but also misunderstanding."