Bava Metzia 39: Apotropos - Guardian and Custodian

More on the property of captives. When it's time to harvest from a captives crops, the court appoints a supervisor to take care of that, and then a relative takes care of future planting, and so on. But that kind of administrator would rarely be appointed for an adult. Also, the story of an old woman who has 3 daughters, and she and one of the daughters are taken into captivity. One of the other daughters has died, and left a minor heir. How does the old woman's property get handled? How does an apotropos fit in here, to help the minor?