I mostly liked I Don't Know How She Does It, all the way up to its unbearably sappy ending (more about that later), but it could be that my standards are lower than yours; since I do have kids, I tend to enjoy any novel I have time to read from start to finish. I'm also a midrange Anglophile, and so I was pleasantly disposed toward it anyway.
I agree the strongest part the book was the voice of Kate and her "Must Remember" lists. Although an obvious homage to Bridget Jones (or perhaps a plain old rip-off?), some of them read like James Joyce reincarnated as stressed-out mom. Kate's inability to prioritize (which, as a woman with a head for business, you think she'd be better at) is an accurately observed symptom of having little kids at home. "Passport expiring please God no. Ask cool friend what gangta rap is. No cool friends. Make cool friend. Downstairs ballcock Richard? Pay newspaper bill/read back issues of newspapers, call nanny temp agency if Paula still ill, see amazing new kung fu film—Sitting Tiger? Sleepy Dragon? Trim Ben's nails …"
As for your accurate observation that Kate in her affluence is one of the most lucky to have ever walked the earth: absolutely. And let me say I'm not generally one to begrudge the middle class their difficulties. I'm fed up with the constraining idea that only the beat-up, beat-down, dirt-poor, misunderstood chicks that appear in books sanctioned by Oprah are worth rooting for. In the case of a mother like Kate with a great job, sleep deprivation is sleep deprivation is sleep deprivation.
That said, I do wish Pearson had given Kate the insight to realize how lucky she really was. The novel is exhaustive—indeed, one of the things I liked about it was the fullness of Kate's world—and could have easily included one of the secretaries at Kate's posh office, or better yet, the woman who comes in and cleans at night. She probably works two jobs, has some low-life guy who isn't nearly as dear as Kate's helpful architect hubbie Richard, and still can't make ends meet. (Any idea how heartbreaking it is to work your ass off and not be able to afford to give your child the kind of grand birthday fete Kate rolls out for Emily?) Likewise, there's the scene where Kate can't find a place to take the family for school break because she's booking too late. Disney World, booked. Euro Disney, booked. Maria, do you have any idea how much a week at Disney World for four costs?
Which brings us to that whiff of manipulation you mentioned. I had the same feeling, only it took a different tack. While Kate was supposed to gain our sympathy as the average working woman, she clearly was not the average working woman. When she does have a spare minute, she zips into a shoe store and drops about a grand on shoes. She buys a nice little black dress at Barneys she has no occasion to wear and doesn't even look at the price. I think this is meant to convey irony: Kate can't be home to put her kids to bed, but she can buy all this stuff! But the effect it creates is the same one I experience when watching Sex in the City: What sucky love lives, but they sure look fabulous in their misery!
What I found more curious was the thing you mentioned about trying to explain away Kate's anguish by giving her an alcoholic father. I felt a little cheated, as if Pearson herself wasn't quite sure we'd feel sympathy for her character without giving her a miserable childhood. This undercut the whole premise of the book, as if to say, "See, only a woman from dysfunctional family would have this devotion to her work." Isn't the point supposed to be that women enjoy meaningful work as well as men do?
Also, congratulations on your own upcoming motherhood. As for those lamebrains who suggest you might not be ready—if it was that difficult, this world would not be groaning with humans, and we would all be only children. The key, I think, is learning not to take oneself so seriously. Hear that, lucky Kate?
All my best,