I'd really like to see a study specific to female happiness with children. I live in the US, and I think men and women's experience with children is entirely different. When my wife worked, she missed our kids tremendously. Almost 75% of her take home went to day care. She was pretty miserable. Now she stays home. She gets a lot of off-hand comments from other friends with kids about "how bored they would be if they…
Any negative comment, any off-hand comment needs to be squashed immediately. Same thing happens with self-esteem issues I think. If the negative comments don't stop from 'friends' you have to make the sometimes tough choice to find better friends. I make sure to say with force how much she does, how helpless I'd be or what a mess I'd be without her help at home.
I think like yourself my mental state is strong enough that I choose lowering myself to lift her above the haters.