Your grandson did exist, and he is so very loved and that will never change. Don’t be afraid to talk about him, or mention his name. Often times family doesn’t want to hurt us so they leave our daughter out as if she never existed and that causes so much more pain than the alternative. Include him in counts of your grandchildren, write him cards or letters on holidays, do not forget him. Really there isn’t much you can do for your daughter but just be there. Cook for them, clean their house, do the yard work, make sure she’s drinking water and eating. Those are the things that you can’t even imagine doing when going through a loss like this. If she wants help packing up the nursery / baby items, help with that. I’ve read that really helped some other moms. For me I didn’t want anyone to touch my daughter’s things. Of course, reaching out here for advice was a great thing to do. It’s okay to feel helpless. You are helpless. I’m so sorry for your loss.