But, you think, it feels so brutal to tell them what the adult realists among us may know for months or years, that Mom or Dad has metastatic disease or a type of cancer that almost always kills.
Read a little further and you find that some of the experts don't think you should be that honest.
"This does not mean that parents should tell their kids everything they know as soon as they know it," cautions the American Cancer Society.
As the NIH concedes, this leaves parents seeking a delicate balance between "avoidance and confrontation."
It also can leave them feeling guilty, frightened, and utterly unprepared to perform one of the most difficult jobs a parent can face.
"It's always hard. It's hard to say, 'This is an illness people have died from and we're hopeful.' Even that is hard. Everybody struggles with that," said Grace Christ, a children's bereavement expert at Columbia University who wrote Healing Children's Grief. "I think even the research centers don't do enough to help families."
People who work with families coping during the illness and after a parent dies say more effective treatments have made deciding what to tell children and when to say it even more difficult. Some cancers still kill almost everyone they strike, but it's harder to guess when the deaths will occur.
Some experts still say it's better to let children, especially older ones, in on the secret quickly. Some say most people wait until a parent is entering hospice, and that's about right. Others say to dribble out the bad news over time while answering questions as truthfully as possible.
Basically, there are so many variables - the parent's specific illness and coping style, the children's ages and coping styles - that there are no simple answers.
