Even though she is pitching, she is still the listed DP for the game, therefore, the FLEX player can replace her on offence and the DP still has a re-entry remaining. ESPN listed her as the defensive position she was physically playing, not what she was listed as on the lineup.
So if I understand correctly, the coach had burned a substitution before the game started?
.They could do the exact same thing if she was not the DP, because everyone has one re-entry
In NCAA, only the starters have a re-entry. If a sub comes in and then leaves the game, they are done.
Yes, as I understand it, the moment Traina started pitching was a substitution of the FLEX. Then when Traina got a hit, and the FLEX came in to run (re-entry of the FLEX), it was a sub of Traina. That's why the next time she got a hit (after she had used up her re-entry) she had to run herself (no pitcher courtesy runner in NCAA apparently).
Moving from DP on the bench to DP Pitching is not a substitution for the DP, and isn't a substitution for the Flex unless the player that moves to the bench is the Flex.