Although I have recovered very quickly post radiation I actually started missing work the first week of radiation. By the 2nd week I was out of work and by the third I was in the hospital on a morphine drip. That is NOT a normal experience, I just tend to be sensitive to medicines and I guess radiation. Most people never end up in the hospital due to radiation. Once I was released the finished up the radiation and added some for time missed I had very little problem with the final treatments.
I returned to work Parttime 1 month after radiation and full time after that. Of course I sit all day but I am an insurance agent so I talk all day which of course was difficult at first but improved daily.
I suppose my point is that it depends on how your body handles it there are NO rules and everyone has a different experience.
As to what to do spend time with those kids as much as possible.