baserunning during an infield fly

Question
I am a new coach in an adult co-ed league. I THINK I have a pretty good handle on the Infield Fly Rule. My question pertains to the fielding and base-running AFTER the umpire calls the out. My team was in the field. Runners on first and second. Pop-up to the deep right side and the umpire LOUDLY calls the Infield Fly rule in effect. No problem. My first baseman catches the ball. And then I realize that the 1B runner has advanced half-way (I watched the ball and did not see when they left the bag). 2B runner is startled into running! I try to yell at my first baseman to tag the runner who is now trying to scamper back to first. But she is instead trying to call Time-Out, not realizing the ball is still in play. My question is...assuming either scenario of the baserunner leaving BEFORE the catch and/or AFTER the catch...how must we get that runner out as they try to return to first? Tag runner or touch first? Does it matter? What about the runner heading to 3rd who left AFTER the catch? Not a force out so I assume that must be a tagged at third.
Sheesh...this stuff never gets easier. Thanks...Val

Answer
Hi Valerie,

An IF is exactly like any other fly ball except the batter is out regardless if the ball is caught or not.  If the ball is caught runners must tag just like any other fly ball.  If the ball is not caught runners can advance w/out tagging.

So R2 going back to 1st can either be tagged of throw the ball to 1st for a live ball appeal of a base left too early. R2 since they legally tagged must now be tagged out.

An IF is a live ball time will not be called during play.

Mark