The picture is cut off. I watched two hours of it. The location of that event which is not included says White House side lawn /tent. She was on the White House grounds. This might prove (what what you say) that fanni was alone with VPOTUS in transport to the White House.
The White House visitor logs for that event shows 446 people attended. James Clyburn was also on the list, as was Yamiche Alcindor (NPR), and Benjamin Crump.
-PJ