Unlike people in the real world, people in Nancy's world tend to find a place they like and stay there unless you shift them.
How do I get people to leave their spots?
Lily is always in the residence tent on her bed, the middle one on the left.
Abdullah is always in the main chamber of the tomb, at your left as you go in.
After you find the burial chamber --
Finding the Burial Chamber
-- two more people will show up. Dylan is always in a chair next to the water truck.
Jamila is initially at the end of tunnel 2. After you dislodge her, she moves to the large room in the middle of tunnel 3 and stays there.