Is this response going to be part of a larger essay in which you explore the different ways in which Rukmani changes? If so, you might like to think of your first paragraph as being something of an introduction. What is key to focus on is the way in which Rukmani begins the story as a naive and very young girl, who, through the course of the story, experiences great hurt and suffering, yet manages somehow to triumph over those experiences, learning great wisdom and becoming a stronger and more indomitable person at the end of the tale. Consider this description of Rukmani from the final chapter:
Ashes and dust, scattered to the winds, moistened by the rain, unrecognisable. I picked up the fragments of my life and put them together, all but the missing piece...
Even after suffering the death of her husband and being alone in a different part of India away from her family and friends, Rukmani shows incredible resourcefulness in the way that she is able to make some kind of order from the "fragments" of her life in the midst of the "ashes and dust" that blow around her in a richly symbolic fashion. This is something that the young peasant girl whom we meet at the beginning of the story would never have been able to do.