Bloodyschool,
I think it depends on a range of factors as to whether its good for any child to catch it.
When we took DD 1 to showing around day at local school the teachers told us it was in the nursery. One parent with us said " Yeah, thats fine, she is going to get it anyway." They went ahead with the tour. I did not,
I was not well, my DD 1 had had a very nasty run of virus and colds and was extremly thin at the time and I was emotionally drained and did not want to have this to deal with, nor for it to be inflicted on my DD at that time.
When she caught it, a year later, she had been healthy, I was also well and we got through it fine.
If my DD 2 catches it by accident somewhere - fine, however at the present time she is already hacking and coughing, has a nasty cold as do I, as does my DD1, we are exhausted from sleep deprivation and dragging ourselves through the days.
I do not want my DD2 to have this inflicted on her at this present time.
I might also add that whilst complications happen to a small few, they happen to someone. I do know of people who have had nasty cases of the pox, so its not something to be taken to casually.
I am more than happy for my dd2 to get it when she is older and stronger.