Why are you so mad about it? The answer is completely obvious: if her startup is offering below market rates to guys and they join anyway, they are apparently passionate about what the company does or motivated more by the promise of future wealth than day to day salary. These people will naturally have more energy because they believe if they put in 110% they'll get back 200%.
Almost without question the interview process was also eliminating men who did not seem energetic or interested in the company.
But she wanted to hire women. So, the women were hired at market rate or higher. Without question they were willing to make an offer even if they had doubts about the woman's energy or passion or commitment to the company. After all it's hard enough to make an offer if you have standards, let alone make an offer to a woman, so the last thing you want is a technically capable woman being rejected because she seemed a bit tired in the interview. These women may have joined simply because the wages were good, without any particular belief or care about the future of the firm. They will work exactly as much as needed to earn their salary and no more.
There's nothing wrong with such workers, it's a fallacy to believe all employees must be passionate. However if your process is selecting for passion except when the candidate is a woman, then the women will seem low energy in comparison. And their "I don't care, why do you care" attitude will probably rub off on the rest of the team too.