Harry's role in this young family's life is an important and unique aspect of the bond that has developed between William and Harry. This, in turn, can also inform our understanding of sibling relationships in general.
At times, you will hate your husband. I know he's Prince William, but he's still a man, a new daddy and human. You will hate him for not being able to nurse the baby. You will hate him for not reading your mind. But you will also love him like you never thought possible.
Some people might tell Kate that the birth experience doesn't really matter -- that all that matters is the healthy arrival of the third in line to the throne. Hogwash. Women care about the experience and remember how it happened.