Forgive me if this sounds insensitive, but are you planning on canceling no matter what? If she passes in the next few days, would you still go?
This is morbid, but in my family, we do a Disney trip after every tragedy. We went after both grandparents passed (once I was a child, once an adult) and it helps to kind of keep things "normal." It might be helpful for your kids.
Good luck.