blame. We don't even know if a contract was involved (you can buy a phone and plan with no contract). Also you can even enter contracts with minors its not illegal, its just that the contract can't be enforced by the company who entered the contract with the minor. So its one sided T-mobile must do what they agreed to but the minor legally doesn't have to do what the minor agreed to. T-Mobile is dumb for getting into contracts with minors but it in no way is illegal or would give them any fault with what she does with it.