She's not pretending, she's scared. Her father left, her mother disowned her, the world ended and Loki never came. On top of dealing with all of that, she's undergoing profound personal changes. Her sense of permanence is shot; she's surprised that the sun still rises in the east.

"Yeah? You have animals that purr that you keep as pets?" She's just talking about cats, man. Cats are cool and sometimes are assholes. Kind of like her.

She's all smiles at the idea of seeing more of him before he goes. "That would be nice. One last chance for fun before you go back to being the best captain in the galaxy?"