For those wondering about how such a fall in the water would affect her ability to get pregnant. Actually, it is true scientifically that falling on the back affects the ovaries. And she fell on her back as it was shown. And such a fall on the water hits hard when you plunge flat, on the back or stomach, without creating an opening on the water surface. Not to mention she was thrown not even plunging. Think about when swimmers plunge, they always go with their hands or feet first to create an opening for their bodies to enter the water. And they either plunge vertically or sitting but never horizontally, it can kill sometimes. Because the water surface would repulse anything falling flat into it As a first reaction before actually opening. It would act as actual solid strong surface as a "shock reaction" then it opens. Anyone can give it a small try by giving small slaps with the palms flat open on the surface of the water, a repulsion would be felt right away against the hand before opening up.
Kamen no Hanayome