I found this story over at Lisa's CB site.
The Strength of an Egg
by Juliet Freitag
Parents of children with cancer, or really any serious condition, are often referred to or viewed as having strength "like a rock." Albiet flattering,it isn't quite true. It is more like the strength of an egg. An egg, you ask? Yes!
If you'll think about it, you'll see my point. An egg has a polished, smooth outer appearance, with no cracks or weak spots visible. It seems almost inconceivable that the inside might not be so smooth or solid.
Most children, at some point are shown the famous egg trick. An egg set at just the right angle can withstand enormous amounts of pressure and cannot be cracked or broken. Yet the same egg, tapped gently at an ever slightly different angle, will break. The contents, once so neatly concealed, will come spilling out. The no longer perfect shell will be crushed. It looks so fragile that it seems inconceivable that it ever held any strength.
A rock, on the other hand, is solid all the way through. To break it is almost impossible. If you succeed, you will find that there is nothing inside but more rock.
It takes a lot more than pure hardness to hold the hand of hope. Parents of [medically fragile] children are not solid all the way through. We hurt, we fear, we cry, we hope. It takes a very careful balancing act to keep the shell from being shattered. "Balancing an egg" while running a household, going for doctors' visits and hospital stays, keeping the family together, and holding on to the constantly unraveling ties of your sanity can be very tricky indeed! Occasionally, the angle will be off and the shell will break, shattering hope and all the neatly secured appearances of a truly fragile existence.
Unlike Humpty Dumpty, though, parents of [medically fragile] kids will pick themselves up and put themselves back together again.