The OP’s daughter is 16U. But to answer your question at 14U my DD was one of four pitchers and getting about 25% of the innings. Later one pitcher switched to just infield and innings were divided among three. It was about 40-30-30. DD’s was one of the 30 and got more than enough circle time to develop. Most of the improvement comes from practice so they don’t need more than half the innings. The ones who claim they do just wanna see their kids pitch.
DD pitched for her 12u C team this year as one of two pitchers. During league nights (3-4 innings; double headers) it was never a problem. But for tournaments it sucked. If we couldn’t get a third (or even fourth) pitcher they were absolutely gassed if we were able to go deep over a couple days.
Now that we’re moving up to 14u B my view on having 4 in rotation has changed. I used to be a 3 max guy. But if you’re team is playing higher level and longer tournaments….4 is nice to have. DD loves pitching, but isn’t a kid who feels she has to pitch every single game. She’s fine sharing.
We’re trying out for a team who likes to have 4 pitchers on the roster. And the coach likes to “pitch by committee”. Pros and cons to that. But should mean that (if DD is offered a spot) she should get her share of time.
I’d think that if DD starts to exceed over the other pitchers than her percentage of time will increase. I’m fine with earned share if that’s the case.