They are sweethearts - love the names.
I forgot to ask my normal questions - what type of food/treats do you feed?
I do agree the ramp may be a bit steep, but the others are maneuvering very well, so....
I'm inclined that she may have something going on with her sight. Offer a good poultry that includes Vitamin A and E. Move you hand slowly on each side of her face to see if there is reaction - if she responds or can you sneak up on her
Her feathering is a bit concerning to me compared to the other lavender. It may be that she is not roosting and getting the tail feathers dirty and they are being rubbed against the sides of the coop, but they look unkempt. Does she take dust baths and preen?