My DDs pitching coach has told us to keep her pitching until either velocity goes down, form changes, or any discomfort. He said he has some girls who can pitch twice as many pitches in a day than other pitchers. Just depends on figuring out each ones limitations. Not sure how accurate that is, but kind of what we’ve been going off.
I'm sure a college coach is going to find the limit of all the players eventually. It's just part of the process.