Oakley or Potts
![Ross](/clue/static/ross-mug.min.png)
I believe the answer is:
annie
(Other definitions for annie that I've seen before include "Oakley, Laurie or Hall" , "girl instructed to get gun" , "Inane (anag) - girl (with a gun?)" , "Musical about markswoman" , "Girl with gun in musical" .)