Good thinking! I will start with a foot and leg inspection.A possible clue here is time of day. Something hurts enough by the end of the day that she doesn't want to fly and land on the ground again, or fly up again? Less pain to just stay where she is. Maybe wing pain as @MaryJanet writes, but more likely it could be pain in her legbones & tendons, or her feet. Is there a way to test that, like give her a pain med for a couple of days and see what she does?