Your girlfriend is not a foreign girl, right? Chinese women B cup is not small at all, and is only 19 years old, the possibility of super C catching up with D is very big ^_^, congratulations! Chinese women cup statistics authoritative data:

A cup: 39.7%

B cup: 47%

C cup: 8%

D cup: 2%

E cup: 0.8%

F cup and above: 0.5%

other: 2%