My parents are coming with me to an admitted students visit, but while I am at departmental events, they will be touring the area and the school. I am SO happy they didn't expect to go to the talks, lunches, etc. that will be taking place, because I agree with your thoughts about them being a stakeholder. They're coming along to be supportive and see the area that could potentially be my new home, but also taking a backseat. I think it would be kind of weird if I brought them around with me to meet other graduate students and professors.