As others have said, bag drop and boarding no issue. But I must say I would draw the line at bringing someone into CW so they can disembark together. I can understand the crew sometimes moves people up to the front of the aircraft in case of tight connections. But if you want to go through the arrival airport together, just wait at the top of the jetty. In other words you cede your place in the queue to be with your friend, rather than have her jump the queue. I think that is the correct approach.