You are deeply in the grieving process. I know there are not adequate words I can say to help you through this, but there are a couple sites I can send you to.
The first one is the one dealing with how to handle it with Siblings. It is very well done, (written by two Doctors who specialize in this field) and will answer your immediate questions in handling this with your daughter.
Site for dealing with Children and grief
This next one is for you.. It will explain the grieving process, and give you links to visit to help you through this.
Healing Hearts - Bereaved Parents
Lots of prayers going out for your family right now. If there is ever anything I can do.. please don't hesitate to ask.
May God comfort you and hold you in his arms during this most difficult time.
Support Bump!!
First, thank you for praying for us. And thank you for reminding me of something important that I omitted. I would like to ask that prayers be said for my wife's OB/Gyn. He's known my wife for over 20 years and this hit him hard as well.