If it is marek's it can take a long time for the nerves to heal and grow new connections. I had one marek's bird who was like that, but both legs. She eventually recovered after 6 months. You can do physical therapy with perching exercises. if it she doesn't seem to be in pain.I have checked for bumblefoot, still no signs. Also it's like somedays she can grab with her toes and some days she can't, I have no clue what is up with that.