Gervaise's frown only grew deeper the more he observed his wife. If the problem had been with her body, that would be fine. But… it most definitely was not.
The body of a Ninth Dimensional expert wasn't so easy to harm. A normal woman's body might break down after giving birth to so many children. Putting themselves through so many changes continuously was bound to have an effect.
However, not only was a Ninth Dimensional expert's body far more powerful, their lifespans were such that this was also much less of a worry.
If a mortal wanted to have 16 children and work on her 17th like Leonel's grandmother, Roesia, was, they would likely need to start having children as early as possible, and they would have to be pregnant every year of their physical peak. Otherwise, their bodies would become too weak to have children by the time they got to their late 40s and beyond.