Well, it should go where the Conflict of Interest Act goes now, which is not just to immediate family members, but also relatives. It was entirely appropriate for the Ethics Commissioner to find, for example, Minister LeBlanc guilty when one of the bids for a contract he approved came from a cousin.
You just have to be aware of these things. Every minister should have a list, and all of their staff should have it too, of what their interests are, who their family members are, and what businesses and other organizations they're involved in. They should be checking that list, and checking it twice, to make sure that they're not involved when they're not allowed to be.