Silver haired's girls boobs are even bigger O.o How is that even possible? Is she like Rias' mother or something?
Actually Rias is still bigger than her, at least if you go by their data. Rias has a 99cm bust while Rossweisse is 96cm bust. Rias has the second largest bust in the series while Rossweise has the fourth largest bust in the series.
Akeno has the largest bust at 102cm & Kuroka has the third largest bust at 98cm