DD age 13 will wear a mask whenever she plays IF or P or even taking grounders in practice. This is not optional, it is a condition of her playing. I wish I knew about these when she started 10U and her coach knocked out her front tooth in the last practice before 1st tournament. Tooth hung on for 3 years but recently required a root canal. She'll have permanent crown and cap forever.#1 Until your DD is hit by a line drive, it is impossible to pass judgement.
I won't pass judgement on anyone who won't wear a mask, god knows I played years without one. But I do tell parents that a ~$40 face mask is a lot less expensive than cosmetic dentistry.
DD age 7 wears a mask only when pitching because her league uses the squishy incrediball but if she moves to a tournament team or older league where they use a real hard softball, she'll be wearing a mask too. In fact I require all the pitchers on the 8U team to wear the mask when pitching unless parents tell me specifically it is OK for their DD to pitch without one.