Well if your talking about the scene in Kill Bill 2, where the Bride tells the other assassin that she is pregnant, it means more then "please don't kill the innocent life inside me". The Bride is making it clear that she is not part of that livestyle anymore, that she is not going to kill the person she was sent to kill. Also I think when you are pregnant it is natural to want to protect the child inside you, even if it was an unexpected pregnancy. The way both women responded, I think is true to what would occur in real life. Its actually kind of humorous when the other assassin leaves says "congratulations" as she leaves. It also showed these assassins were not heartless women. However the other women in the film and Bill who try to kill the bride are heartless.

A similar scene occurs in Kill Bill 1 in the first battle. The bride says she will not kill the woman in front of her child. I don't see why compassion is sexist.