I would go without the family member. You're an adult now. You can do it. If the family member wants to visit the area, that's fine, but they shouldn't come with you to the waiting room or take a tour with you. Even if they're helping you financially, they can take a tour later. This isn't undergraduate school, where parents accompanying students is common. At all the interviews I went to, I hardly saw any parents. If you bring your family, you'll be one of the few applicants with a family member, and I think you'll give the impression that you're young.
Kevin