Over the weekend I was at a restaurant and it was apparent that it was a family operated business. The staff was very friendly and it seemed like everyone was in tune in trying to achieve a common goal.
This got me thinking on how some people say working with family members in a business is great as you can fully trust the people you are working with. The other side would say that it is a horrible idea as working with people you know very well tends to cause a lot of conflict.
I think the key thing in this circumstance is to make obligations clear while being firm with business issues as you would normally.