Bring the family, just make sure they have appointments. Just imagine, you have submitted Global Entry applications for the entire family and everybody received their notice to schedule an interview at an enrollment center. FYI, since the applicants backgrounds are investigated, multiple applications submitted at the same time rarely are all approved at the same time (see Q&A). Now you want everyone to go together in one trip as chances are you will need to travel to visit an Enrollment Center, what are you to do? You have two choices, the hard way, locate the closest Enrollment Center and based off of the availability coordinate times and dates; once that is done, login to each and every account as you will need to schedule one appointment per person. Easy way, call the helpdesk! They can quickly let you know what Enrollment Centers are close to you, let you know what times are available, schedule everyones appointment in about half the time it would take you, and you would get a confirmation that everyone is scheduled. The important thing to take away is that there is no one appointment for everyone and to schedule soon (30 days) to keep your application from being cancelled.