Papasmurf said:
Well Roshi does call her very skilled at martial arts, but he said similar things about say Chaozu in the 22nd despite being weaker than he is. Her fight is also hard to glean anything out of since Goku was flabbergasted that this stranger knew who he was when he couldn't even remember her name and didn't strike back until he decided to one-shot her because she told him she'd reveal who she was after that.
Roshi seemed more impressed with Chi-Chi than Chiaotzu. The "Super Master" statement for Chiaotzu was basically Roshi saying that he's superhuman just like Goku and Krillin. Roshi's statement for Chi-Chi was there to create hype by painting her as an extremely strong fighter (hence why he mentioned her style resembling his Turtle School)... he said something similar about the Masked Fighter.
As for the fight... she nearly surprised Goku with her initial attack and was able to push him back even forcing him into the air but still caught up and fought him in the air. The move Goku used to defeat her also shocked Krillin, Yamcha, and Muten Roshi by it's sheer power (Roshi even had a hard time making sense of it) and caught Piccolo's attention (as it is a shockwave technique his Mazoku clan uses)