Can you sue your mother for child support that she is receiving and withholding from you?

Child support is to pay for you to live, not to give to you as pocket money. If your mother pays for the roof over your head and your food, heating, clothes etc then she can be said to be paying for you to live. So you wont be able to sue her. Plus, in order to sue someone there needs to have been a contract between you that she has breached.