I believe tail cutting is generally referring to males with excessive finnage. If you were to trim a females tail it could prove to be very,very difficult There's just not a lot of finnage to work with, not to mention that a portion has already rotted away
uhhhm, there's really nothing left to trim. Can you go get some methylene blue?
If not, maybe you can go beg your lfs for a quarter teaspoon (teaspoon if you're so lucky) to mix up some tonic water for her.
Try adding some aquarium salt or try a different brand of med as you may have a desease resitant strain, also keeping top notch water quality will help.