First of all, as others have pointed out (in particular, the brilliant Rebecca Traister at Salon), "having it all" is an offensive way to frame the problem. No one gets to have it all; using that phrase makes legitimate feminist goals of equal opportunity seem childish, absurd, and materialistic. What people generally want, and are right to expect, is a not-horrifyingly-unequal shot at success and happiness.
As has also been widely noted, Anne-Marie Slaughter speaks from, and largely to, the vantage point of upper-middle-class white privilege. To her credit she takes the rare step of acknowledging this, and I think her arguments are important to bear out despite this limitation. If we want more women leaders in politics, business, and science, Slaughter's problems are part of understanding the barriers to achieving that. So yes, she is in an enviable position of having choices that most women don't have; but if we want more than 17 percent women in Congress, if we want women running more than 3.6 percent of Fortune 500 companies, if we ever want to see a woman U.S. president, the choices of women at the top have an effect on all of us.
What I don't like is her framing of women's choices as more fraught than men's because women inherently feel less comfortable working and spending time away from their children than men do. I respect that this has been her experience, but I haven't found it to be generally true for me or the other parents I know. I would argue that there is a vicious cycle perpetuating more women than men staying home as primary caregivers and thus taking a slower career track or opting out entirely: Statistically women still earn less money than men and when push comes to shove many women find it "just makes more financial sense" for them to quit working rather than pay for child care. Adding to this pressure on women's choices is the still-true fact, surprisingly ignored by Slaughter, that women put in a national average of between 6 and 12 more weekly hours of housework and childcare than men do, even when both partners both work full time. This is an added tax on women's ambition — we could call it the exhaustion tax. It is not just workplace culture that needs to change in order for women to have an equal shot at success. I think that this home imbalance is even more difficult to overcome.
The art world exists within the larger culture and has the same problems, as I and others have chronicled repeatedly. It may be an easier place for women to balance work and family, since artists (at least successful ones!) have control over their schedule. But one has to actually get successful for that to happen, and based on the numbers that seems to be much harder for women artists.
In 2006 I did a survey work called “How Do Artists Live?” Almost 900 artists gave anonymous responses to questions about their income and lifestyle. Among other things, I asked if the responding artists had kids, and I asked if they had gallery representation. Among those responding the male artists with kids had the highest percentage (approximately 50 percent) of gallery representation. Female artists with kids had the lowest percentage (approximately 20 percent). Male artists with kids and female artists without them were about tied, about 27-28 percent with gallery representation.