M.S.
G., I lost my sweetheart of 34 years four years ago at the age of 54. One of our sons was his care provider at our home while I was at work and he'd bring his two daughters to the house with him. One was a newborn and the other 5 years. I worried about the 5 year old as she was grandpa's helper. He had ALS so he spent many months in bed and she helped him do many things that he couldn't do for himself. Most important she was there to talk to him and they had a fabulous relationship. She could see day to day grandpa was getting worse and we explained that he was getting ready to go to heaven and live with God. She was told he didn't want to leave us because he loved us very much but God needed him. We told her that in heaven grandpa would be able to walk again, he wouldn't hurt and that someday we'd all be able to be with one another again. When he passed our hospice nurse was there for all of us and they had a special book just for Kayla. Kayla asked to see grandpa one more time before they took his body from the bedroom. Her mom went in the room with her and sat beside her. Kayla sat there for awhile, touched him and said goodbye. There were tears and there are still tears from time to time but for a barely 5 yo I was amazed at how well she did. She was prepared, knew it was going to happen, asked questions that we answered and has wonderful memories of a grandpa that adored her.
Each child is different. Talk to her now so she has time to think about things and ask questions. It also depends on your own religious beliefs. How is your mom handling the situation? My husband was able to talk to Kayla and tell her himself that he understood what was going to happen. He never made her feel like death was a bad thing and he was amazing accepting of what was going on. I think that helped all of us during a very difficult transition. It wasn't easy but it wasn't frightening either.
One thing I did was to make a handprint of grandpa for each of the grandchildren. I got finger paint, they picked their own color, and grandpa did a handprint next to theirs. So each still has a visual reminder of a grandpa who loved them.
Take care of yourself too. Tears will flow and that's OK. Help one another during this difficult time and leave the lines of communication open. God bless you all.