A point has been raised about the age of contractual capacity, which is usually set at 18.
Minors are permitted to enter into contracts for limited purposes, and the test is one that focuses on the nature of the transaction, and whether the minor is of an age such that they capable of understanding it.
Contracts entered into by children that are for 'necessaries' (e.g. the supply of food, medicines, accommodation, clothing, amongst other things) are binding on children, as are those for apprenticeship, employment, education and service where they are rightly said to be for the benefit of the child.
Non-binding contracts would be those for conveniences, and products and services for comfort or pleasure. Commercial or 'trading' contracts are also excluded. These latter contracts are voidable at the option of the minor, and whether the minor may avoid the contract depends on the nature of the contract.