Who is going to pay your $3000 if your parents don’t? I would NOT bring up the legality. Sorry, but they will find a way to rescind if you do. Have that fight after the internship if you must. Bringing it up on the front end won’t help you. If you don’t have $3000 in the bank and your parents won’t bankroll you, then you need to ask for a salary. If they won’t do it, I presume you will have to turn it down. Those seem to be the facts.