Hi,
I feel so much your pain at what you are going through and the impact on your little girl.
I had a similar situation when my eldest son was on palliative care at age five and my youngest was three and a half. My younger son had seen his brother sick many times but this time questioned as to when TOM was going to get better.
I told him honestly, but very very simply that his brother was not going to get better as his body was no longer working well and he was very tired. I told him that TOM would die and go to heaven to be with the Angels and that our job now was to keep TOM free of pain and to spend time with him doing what he loved, reading, singing etc. My son handled this and I believe he felt he could 'help' by participating.
When he died his brother and I went a chose together where we would bury Tom and I explained what would at the funeral and that Tom would not come home with us.
We chose a star, Venus, which to this day was toms star .... Still today he knows it as such.
Be gentle, be honest and let her participate.
With much love.
Deb