This is a really weird topic and strange conversation about a CEO when you think about it. Did we care what child-care arrangements the last CEO of Yahoo! (Scott Thompson) had made? Why didn't we ever discuss Steve Job's parenting skills and buy/sell Apple based on that criteria? "He's going to Vegas again to a conference and ignoring the kids -- is it time to sell?"
The bigger question -- Are women executives supposed to have a lesser entitlement to privacy than men? This is the implicit presumption of this topic. It is part of what is known colloquially as the "double standard".
Personally, I do not own Yahoo!, but if I did i would not care a whit about her parenting choices and skills, as long as they were legal. I would be glad that she is not a proven liar like the last one, though.
Some of my best mentors in professional life have been women -- at the highest levels they tend to be a bit tougher and more practical than most men, which I am guessing is the result of having to re-prove themselves at each level of advancement. As I get a little more gray hair, I've come to realize than my own competence is presumed. (I am tall and have the famed "executive-style hair" noted in one or more Dilbert cartoons.)
Finally, I note that success in one area of life does not equate with success in others, and often exceptional success in one area is accompanied by failure in others. I recall reading an article a few years ago about famous "bad fathers", who had terrible relationships with one or more of their children. Among the parenting failures featured were Gandhi and Ben Franklin.