Yes, they need wing spreading space to get up there.I'm afraid she can't get up there bc of room, even though there is a whole other roost bar behind the one they all get on.
It's hard to see just where the roosts are in relation to distance from the wall.
Is the highest roost close to the wall(how many inches away from wall)?
Same with 'behind' the main roost (circled in red).
How long are the roosts?