Who flies in the Queen's Wing (other than queens and preggy greenriders) and why are they chosen for the job?
In some cases it might be riders where either they or their dragon have an injury that prevents them from joining the other wings. For example, damage to a wing that has limited the dragon's mobility so that they couldn't fly with a wing at high altitude. Remember the Queen's wing tends to fly lower, mith the aim of getting anything that the upper wings miss.
Pregnant greenriders also are assigned to the wing because it isn't so stressful on the body. But there are also some green and blue riders who are assigned permanently to the wing to give it stability.