For the most part you can't do anything, because its in almost all the terms and condition, no multiple accounts on same ip address. It doesn't matter if you are related, or not.
You may get lucky, and some casinos may not put this in the terms, but most of them do.
You also may get lucky, and a casino may want your business and take what you say at face value, and let you have an account. But if this happens, you also have to worry that your money will not get voided. Because since you are broken the term of the contract.