I think your frustration with the one sided narrative is part of the author's intention. I read and hear her interviewed a couple of times earlier in the year and she is certainly a strong character with definite ideas about things, so I think that she meant for the book to challenge, disturb and undermine conventional thinking. In fact, I seem to remember her on Richard and Judy (!) with two other authors who had written loosely along the lines of not wanting children. One of the other books seemed to be a bubblegum 'I'm not going to have kids because I'm a crazeee chick having too much fun'. The contrast couldn't have been stronger!

I didn't guess the ending (I never do) and was totally shocked, although I immediately felt that of course that's what Kevin would do. I'd assumed that the father had taken the daughter away somewhere.