I think it would make life easier if you clarified a bit. Are you talking about support offered by the school, or not punishing them for misdemeanours, or not expecting them to do their homework?
The nearest I have come to this is a) my own dd who is disabled and in pain herself and b) her friends whose mum died last year after a prolonged illness. The second case seems closer to yours.
In that case, the school offered counselling and the situation was explained to the other children so that they would not tease the children if they behaved oddly from time to time. At the same time, the youngest boy was told very clearly that if he hit other children, punishment would happen as usual; and I believe this did help to offer him some stability. They were given some compassionate leave to holiday with their mother, but when they were in school I think work continued pretty much as usual.