That sounds pretty typical of MBD, they confuse their own limbs as branches, as if they can't feel their own feet grabbing themselves. I am not an expert on MBD by any means, but I don't know if there's more you can do. You can halt MBD but not reverse the effects of it (like the physical signs), I think all you can do is keep supplementing really well with calcium and see if she slowly starts to regain proper motor function of her limbs, but it may never be perfect.
You might have to be creative with her cage. Make sure the pathways are comfortable to use and easy to grasp to compensate.