If the run on 3rd is extremely important, ie, the go-ahead or winning run in the last inning, the 2B should cut it off and throw it home. Otherwise if your catcher has a good arm and can get the runner at 2nd, get the out there.

imo you can either get the force at 2nd with the SS covering or if the runner on third breaks - tag play at home. In some case you can get a tag play with the 1Bman on the bunter/runner if hit hard enough at her. You can also have the pitcher field the bunt and hard fake to 1st or 2nd then whip around to 3rd for potential cheating runner... Or you can just chalk it up to what are you trying to accomplish? Not let the runner from 3rd score? then without getting an out you have done that by holding her at third and creating force plays at all bases and potentially putting yourself in a better position to get an out at any base or turn a DP if there are less than 2 outs.