She was on the top of a steep/diagonal roof and almost on the edge of it. Then she suddenly felt the pain in her gut so she leaned forward and lose her footing. Logically speaking, in that angle you would fall down too.
Are we not moving on yet? Oh, but thanks for the translation, for the third time or maybe fourth time already. Well, the first translation of this chapter isn't bad, too.
I just hope the ratings will change I mean this series is really good. It deserves an 8 or even higher.
Someone else said this manga is not good enough. Like wth I bet they weren't actually reading. Oh well, it's their opinion and it sucks to be them, I'd say.