runner double off after foul fly

Question
The other night in a co-ed slow pitch softball game a young lady was on first with one out.  The batter hit a blopper foul of third.  The third baseman caught the ball in foul territory.  For some reson the girl on first had run half way to second and turned and was walking back to first. The thirdbaseman threw back to first and beat her back to the bag.  The umpire called her out.  I thought on a foul ball you got to return to your base with no penalty?

Answer
Hi Joe,

This isn't a "foul ball" it is a caught "fly ball" that happened to be in foul territory.

You cannot leave the base until a fly ball, (that is caught) is touched by the defense or risk being out on an appeal, in this case it is a live ball appeal.  The call is correct.

mark