Female cockatiels

Molly may either be bored, stressed, molting or a combination of those factors. My recommendation would be to try first, paying more attention to her if you aren't already and/or providing her with a simple toy here and there to peak her interest. If that doesn't help, then try adding some Forti-Diet (brand name) Molting and Conditioning supplement for small birds. I bought mine from Petco, for my female cockatiel, Mojo. Is she getting a proper diet? Proper rest? If none of these things work, then I suggest contacting your veterinarian for alternate suggestions. Good luck!