Hi Kathleen,
Mine were 8, and 5 for surgery and the key was communication. Age appropriate, of course. From the day of diagnosis when my husband took the MRI, an apple which represented my head and he sliced like the MRI, and a superball to show them the thing that didn't belong, and explained what was going on (then they ate my brain (apple) to make light of it!), we have been pretty open. We had the good fortune of spring surgery, so I planted a garden b4, which they tended till I was able to come up and see it. They proudly presented these sprouts happily poking their heads out, and I took my first fall, which put me right where I wanted to be: sitting down pulling weeds. Not having that luxury, you might try "Sea Monkeys" you (your hubby or m-in-law) can get at a pet store or on ebay. Your 10 year old would love them and it would give them something to tend to till you get home and they can tend to you. they can spend hours watching these microscopic things grow and would just visible to you when you come home. My oldest, a daughter, is militant about my recovery - reminding me to keep my hands on the home row when I type (I was having problems with my right side and wanted to use the left for everything), and I hear her say "your OK " when I suggest I can't do something, mimicking me when they take a fall or approach something they think is to difficult.
Some good advice has come before, and knowing what Jim said is true, I tried not to be to emotional the night B4. It didn't work, and that is part of it, and it is O.K. Children are amazingly resilient.
Best to you, and your family. Prayers are with you.
Julie