I asked this on Finance and they said it was a Law question.
Let's say you are an ordinary family, and one of your young children is lucky enough to be cast in a huge blockbuster movie franchise, for which they are paid many millions of dollars.
The income is of course earned by the child and belongs to them. Since they are a minor their parents must manage the money, but are obliged to manage it for the benefit of the child. The money isn't theirs.
However it seems unlikely that the parents continue to work regular jobs, pay the mortgage on their suburban 3-bed house and buy groceries for the family out of their salary while the child is worth tens of millions. But how is this managed, legally speaking, without the parents being able to enrich themselves at their kids expense?
Experience or knowledge rather than guesswork please.