After about 40 hours of searching over the last two months, I think I figured out where we all are relative to one another and the airport and the city of Beijing. It seems part of the problem might be my lack of understanding of the varieties of city name spellings. I could still be wrong, but I will sleep better tonight knowing that we at least appear to be on the same continent as Mar.
On the eastern side of the map, a bit to the right of the middle of the map, you'll see a red airplane that designates the airport. Beijing is southwest of the airport. You can see the ring roads around the city. I believe the outermost one is the 6th ring road. Notice how that ring road is above the airport? To the northeast of the airport, there is a large green mass that is the approximate location of the rowing venue where Margot is staying and competing. If you go west of that area and down a bit you'll get to where I think we are staying -- above the highest ring road that is visible on this map, and to the east of the vertical road that bisects the map. Whew!