substitution or not?

[shipwreck]

I was working a NCAA game yesterday. Here is what happened. Third inning coach decides to pinch run for the runner at second. He informs the plate umpire about who will replace the runner at second. He tells the girl to go to second. She takes her place on second but then he has second thoughts about putting her there and decides to put a different runner on instead. My question is, since he had reported the first sub to the PU, but the PU had not yet reported this to the other team nor the official scorer,is the first girl that took second base considered a sub and is now done for the game, or is it just like she had never been in the game? Dave