Hi Jean,
I did a tahara with the head of our men's team for a 5 day old baby boy a few years ago. The men's leader asked me to help him. What seemed clearest to us both was that this baby was already tahor. Physically he was perfect looking, beautiful, and he had been on life support his entire 5 days.The rabbi did a symbolic circumcision in the tahara room. We used the liturgy for preparing ourselves and I made up a prayer to express our confusion at this death. We did not use liturgy for the physical tahara. We carefully poured 3 cups of water and wrapped him in a small blanket. Very difficult and sad. But it was such a holy experience that I am a little concerned to share this less someone comment negatively on what we chose to do.
A year ago our granddaughter was stillborn, full term and over 7 pounds, for no known reason. My son and his wife live in California, we live in Chicago, and this child died ten days after I had had major surgery. I could not travel to be there when the baby was finally "born" 2 days after she died and never got to hold her. That was made more bearable by remembering the privilege of doing the tahara for the infant boy and the memory of that purity.
I hope it goes well for you. I will keep you and the family of the child in my thoughts.
Deborah