That cliche fall... That cliche "I totally felt breasts there and totally think this person whom I've been thinking is a man has to be a woman"... Come on author
"Lois Lane is falling, accelerating at an initial rate of thirty-two feet per second. Superman swoops down to save her by reaching out two arms of steel. Miss Lane, who is now traveling at approximately one hundred twenty miles an hour, hits them, and is immediately sliced into three equal pieces."
ooof, her ribs were already bruised now they're tenderized.
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.