Rule question

[RLG]

No, my wife is the coach of the HS team and is also an umpire in the summer leagues and fall.
What would you consider the player(CR) on the field? She would not be considered the CR until play has stopped and the umpire has acknowledged her. Can't find anything in FED book that clearly defines the situation, maybe Rule 3-5-5. Does not give the penalty. At least make the runners go back to 1st and 2nd. I would think call R1 out and allow the BR 1st then after fuss have to eject the coach(grin).