Ground ruled double

Question
Does an umpire have any discretion as to where he places base runners on a ground ruled double or must they only advance two bases along with the batter? In a U14 girls game witha runner on first a girl hit a ball down the left field line. The ball hopped untouched over the left fielders glove and then rolled for quite some time before it eventually passed the in play boundary. The first base runner easily scored. Should she be stopped at third or does the unpire have the discretion to determine she would easily havr scored and award her home? Does the fact that the fielder had a clear play and missed the ball have any bearing?
Thanks

Answer
Hi Gary,

This is a problem on fields that are not enclosed and can seem unfair to the offense.  The rule on a fair batted ball that goes out of play is 2 bases from the time of the pitch.  It doesn't matter that r1 could have advance further or that F7 could have made an easy play.  R1 on 3rd and B2 on 2nd.

Mark