Who are you to judge her priorities? Watching an infant can be brain numbingly tedious, and so can sitting in waiting rooms for hours at a medical office.

Maybe the startup gives her husband a positive distraction to focus on instead of his treatment and it gives them something good to talk about. You have no idea.

A startup might be the perfect antidote to balance out her other duties to her family.

Remember that all people are not equal, some people are in the top 1% of population for energy, or IQ, or organization, or even with a need for sleep. Aka do not attempt to measure this woman against the "norm", she is probably very very capable and can handle everything better than most.

All of us have a unique blend of skills and abilities, and it takes less effort for some of us to fulfill priorities than others.