Seems a bit strange to me, if I call a plumber to fix my heating and they tip up with 2 people, I would assume that each guy costs X amount per hour. So long as they know what they are doing, what's the problem?
If a company want's you to work on hourly rate, then why do they have to know if the people you employ are family members, or what football team they support, why should that effect the hourly rate you charge?
If we get jobs that need to be done on hourly rate, it's X euros an hour, the fact that I work with my wife has nothing to do with it. I have part time help when I need it, and charge full rate every time. Don't be afraid of earning what may appear to be a high amount of money per hour, that's one of the reasons for working for yourself IMHO.