While she may have a better view without the mask, if she got hit in the face with a ball, not only could the medical bills be expensive, but her face may never look the same. She could also suffer from breathing problems, broken teeth, and if she is hit hard enough there may be far worse medical conditions that arise. Masks and helmets are there for a reason, and should definitely be worn.
If she has decent hand eye coordination I wouldn't worry about it. She probably just doesn't want to be embarrassed in front of her friends, which is understandable. A mask at shortstop seems like overkill. I played baseball from age 7 through high school, the only time I wore a mask was when I was catching. I did get a couple black eyes but it taught me that I better catch that ball Lol. Ultimately its your decision though. You are her mother
i was an infielder for 35+ years and took a few in the coconut. no big deal if she takes one in the MUG she wears the BLACK EYE as a badge of honor i wish her well in her softball career.............GO RED SOX :)