I have a DSIL who's an hour from WDW. When she comes over to visit when we're down there, she gets to the gate and tells them she's here to visit the _____(insert name here), the security guy checks on the list to make sure the ____ are registered guests, and lets her in no problem. If you want to be extra vigilant, call security and tell them you are expecting a guest. I have done that too, and they seem to like it.