I agree OP. My son has just sat his GCSEs while his sister has Stage 4 cancer. He has had to deal with his own emotions and those of us his parents who are devastated.
It is the day to day impact these kids suffer of listening to his sister crying in pain, losing her hair and absent parents staying over night at hospitals.
5% is the maximum award that is given, I imagine for the actual death of a family member.
When I spoke to the school they were overwhelmed with dealing with sheer explosion of kids needing extra time to complete exams due to SN they said it was unfair but all they could offer was to ask the exam boards to consider his situation and we wouldn't be told what their decision was. No extra tme was offered as we'd missed the deadline to ask.
We will be proud of him of whatever his results are. His sister is racked with guilt.