I am not sure there will be an exact answer to this question. It can be reduced to upon what an individual places value. For example, if I value loyalty above all, then as the postmaster, I take Ratan with me. When she asks to be a part of my life after having given all of her devotion to me while in Ulapur, then I take her with me to Calcutta. In valuing loyalty, I don't think that there is any other choice but to take her to Calcutta. I think that the postmaster's actions are fairly selfish, and I feel that if I am in his position, I value loyalty above all. It is for this reason that I take her with me to Calcutta.
There is something painfully sad about how devoted Ratan is to the postmaster in asking if he can take her with to Calcutta. His dismissive laughter is the height of disloyalty. I think that in valuing loyalty, I would take her with me. Ratan does not have anything that is keeping her in Ulapur, as her life had been given meaning with her loyalty to the postmaster. In his position, I would honor that by taking her with me. I try to be as intricate and as open to nuances as possible. Yet, somehow, in this particular instance, I find myself rather hard- lined in what I would do and critiquing what the postmaster didn't do.