We have a lot of solutions for many different solutions. As I see it with NFHS rules, there are 2 possible solutions.
1. The runner must be tagged to record an out. This may create a rundown, that will establish her base path "ONLY" when an attempt is made to tag her. If there are multiple throws to tag the batter/runner B2, she creates a new base line with each throw, so the 6' base path can change with each throw. It is not always a direct line between 1B & 2B.
2. throw the ball to the pitcher and force the runners to go directly to a base LBR in force. I would rather give up 2nd base than a run.