In wanting to say something consoling, I usually end by saying something stupid. Still, my heart wants to reach out to you, b/c you have had an experience forced on you that you didn't choose or want.
I know your main concern is your child. And, I think you are going to feel almost every negative feeling in the coming days. All I can tell you is to allow yourself to feel it, without expecting more or questioning yourself.
With every loss of a loved one in death, our reaction varies. I have learned through my own experiences, that the surrounding circumstances connected to that loved one....determines our level of inner turmoil, as we try to find acceptance and peace in figuring out how we live with their absence.
You will be very sensitive to what others say. Just try to remember, most people feel impressed to say something....but they don't know how or what is appropriate. Asking how you are doing, for example, may seem so crass.......but it's what people say out of habit and custom.
Please accept my heartfelt condolences for you and your child.
It is not about what you feel should work in your M. It is about doing the work that gets the right results. Do what works!