Sarada has never met her dad so all she knows are rumors and what people tell her, by Chochou's explanation it's still prevalent that the Uchiha are still a clan of exceptionally strong shinobi so she still has that pride in her heritage. Also technically noone knows that sasuke has a rinnegan by technicality except for Naruto, Kakashi, and Sakura. And probably orochimaru, Karin, suigetsu, Hugo and kabuto depending on if sasuke faced them after he asked the 2nd to teleport him too naruto's location. If a wide range of people knew sasuke had the rinnegan then well....noone would be messing with sarada, you saw what happened with pein and sasuke is leagues above him.
