Defensing a play

Question
This question is actually directed towards little league softball but I was hoping you could help.  Keeping in mind the skill level if you have a runner at third and the batter walks.  In little league we often do a move where we have the walked batter continue running to second base.  The goal of this play is to confuse the other team into a mistake in the hopes the runner on third will score.  Problem being from a defensive standpoint is it often works.  How would you suggest handling this play during different situations?

Answer
Mark,
You didn't mention how old or the ability of the players, but I defend this as follows.
Have your catcher throw down to first, first baseman should be standing between first and second about 6' from first, the walked girl cannot step off without getting tagged and the first baseman can watch the runner on third. When the girl gets to first, first baseman can throw the ball to the pitcher. Make sense? Good Luck, Coach Suthe.