I don’t think that is legally possible.
Even with the change of succession law allowing Charlotte to be Queen if born first..she still couldn’t have inherited the Duchy of Cornwall purse. Goes to first born son
Re Cornwall...looking to the future, Charles was trying to get hapless Harry to help...NOW. Harry couldn't have cared less if he tried.
Yesterday the DM has a nice article about it all and how Wills is now stepping up. Go read it.