Originally Posted by
GoingAway
IAD will let you in once you have the F boarding pass in hand, you'd be her guest. As others mentioned, Arrivals is a non-event at LAX, but you'd have access there as well as her guest in both direction. The rest of the time both of you have access to the clubs as *G and a premium cabin passenger.
According to 1kvoice:
Passengers holding international first class tickets on any Star Alliance partner are allow access to any United International First class lounge at the departing airport only. Passengers holding international first class tickets on United Airlines are allowed access to any United International First Class Lounge through the entire itinerary at departing and connecting airports. Companions are not permitted.