Siblings aren’t always treated the same. It’s not always the best practice for parents to do the same thing for each kid because every child has different needs. You wouldn’t give intensive therapy to a kid who doesn’t need it just because their older sibling required treatment. On the other hand, it’s pretty stinky to pay for one kid’s dance classes and not the other’s if they also wanted to do it. Life isn’t fair, and the family is the first place where you see that in action. 

The prolonged illness of a child can often cause unequal treatment between siblings. The siblings of chronically ill kids, known colloquially as «glass children,» are similar to Mr. Cellophane. People look right through them and walk right by them without knowing they’re there. Although they may appear strong, they are incredibly fragile (one of the main differences between glass and cellophane).