What sort of holiday can be good for a child with cancer and his family?

i have a little cousin called nicole, who is four years old. she is a very spoiled little girl, who always gets upset when she doesn`t get her own way. she was an only child raised by her single mother. aunt rose had recently got married again. her husband is a man called harry, who was a single father. he has a six-year-old son called jason. after the wedding, the two children did not get along. nicole loved to get jason into trouble and jason considered nicole to be the most annoying pest ever. unfortunately, jason got cancer and was in the hospital for ages. he had to undergo many treatments, including chemotherapy, which made his hair fall out. when he got home, people gave him most of the attention. nicole feels ignored and left out. when they go out as a family, jason might not feel well and they have to hurry him home. nicole would cry because she wants to stay and play. her mum and stepdad would just comfort her, saying"we will play later." what can i do to help them?