Neither Rhoda nor Gertrude is presented entirely negatively. Nor is either presented entirely positively. All Hardy's characters are fully drawn individuals who, like most people in real life, are a mixture of good and bad.
Rhoda, for instance, is portrayed sympathetically as the jilted woman. Farmer Lodge has fathered her child but refused to marry her. She has become a "thin worn milkmaid" who supports herself and her son with arduous labor. At least some of her co-workers find her plight pitiable: upon Farmer Lodge's marriage, one whispers to another that "'Tis hard for she." At the end of the story, we learn that she insists on remaining independent and not taking the money Farmer Lodge has left her.
On the other hand, Rhoda has her flaws. Her curiosity about Gertrude, Farmer Lodge's new wife, amounts practically to obsession. While refusing to meet Gertrude, she insists that her son take every opportunity to do so and makes him relate every detail about the bride. When the son first sees Gertrude, she is sitting down, and so he is unable to ascertain her height. Rhoda immediately insists he find out:
'Then do you go to Holmstoke church tomorrow morning: she's sure to be there. Go early and notice her walking in, and come home and tell me if she's taller than I.'
'Very well, Mother. But why don't you go and see for yourself?'
'I go to see her! I wouldn't look up at her if she were to pass my window this instant.'
There's something almost comic about Rhoda's wanting to know every single thing about Gertrude while simultaneously asserting that she wouldn't care enough even to look at her. This is a deeply human portrait: her anger at and obsession with her rival are at once understandable, pathetic, and reproachable.
Gertrude is depicted in a similarly complex fashion, as both a sympathetic and a blameworthy figure. To begin with, she is an innocent wife who loves her husband and wants to retain his love. Her naïve, good-hearted nature makes even Rhoda warm to her when, despite Rhoda's best efforts, the two inevitably meet. When Gertrude's arm is afflicted, her desperate efforts to set it right seem, on the one hand, to indicate her vanity—she wants to retain her beauty at any cost. On the other hand, one reason her beauty matters so much is that Farmer Lodge values it, and without it, she loses his love. The following exchange between Gertrude and Rhoda makes this clear:
'I shouldn't so much mind it,' said the younger, with hesitation, 'if - if I hadn't a notion that it makes my husband dislike me - no, love me less. Men think so much of personal appearance.'
'Some do - he for one.'
'Yes; and he was very proud of mine, at first.'
'Keep your arm covered from his sight.'
'Ah - he knows the disfigurement is there!' She tried to hide the tears that filled her eyes.
At some later point, Gertrude learns that Rhoda is Farmer Lodge's cast-off lover, and that Rhoda's son is his. But she neither attempts to make common cause with Rhoda, nor encourages her husband to acknowledge the boy's paternity, even when Lodge says that he had at one point considered adopting the child. On the other hand, Gertrude has also discovered that Rhoda is in some sense the cause of her disfigurement. This mitigates Gertrude's blame: it is hard to act benevolently toward someone who has wished, and perhaps caused, you to be harmed. Besides, by this time, Rhoda and her son have left the village for parts unknown. So even if Gertrude wished to help them, it is not feasible.
Hardy suggests that both women are in fact victims of forces beyond their control. These are in the first instance social forces, such as the classism and sexism that allow Farmer Lodge to seduce Rhoda, then abandon both her and his own child, then marry the better-positioned Gertrude, and finally spurn the latter when she loses her health and beauty. Secondly, the story could be seen as a psychological allegory, where the overt friendliness between Rhoda and Gertrude masks unconscious hostility that damages their relationship. However, the story ultimately resists any simplistic analysis along sociological or psychological lines. The supernatural streak running through the narrative points to a larger, more elemental entrapment: to be human is to be at the mercy of ill-understood, uncontrollable forces.
Gertrude's withered arm is the central symbol that Hardy uses to depict the complexity of the situation in which the women are trapped. The precipitating act occurs even before the two meet:
Rhoda Brook dreamed—since her assertion that she really saw, before falling asleep, was not to be believed—that the young wife, in the pale silk dress and white bonnet, but with features shockingly distorted, and wrinkled as by age, was sitting upon her chest as she lay. The pressure of Mrs Lodge's person grew heavier; the blue eyes peered cruelly into her face: and then the figure thrust forward its left hand mockingly, so as to make the wedding-ring it wore glitter in Rhoda's eyes. Maddened mentally, and nearly suffocated by pressure, the sleeper struggled; the incubus, still regarding her, withdrew to the foot of the bed, only, however, to come forward by degrees, resume her seat, and flash her left hand as before.
Gasping for breath, Rhoda, in a last desperate effort, swung out her right hand, seized the confronting spectre by its obtrusive left arm, and whirled it backward to the floor, starting up herself as she did so with a low cry.
'O, merciful heaven!' she cried, sitting on the edge of the bed in a cold sweat; 'that was not a dream - she was here!'
Gertrude too relates a similar, simultaneous dream, where she has been grasped by the arm and flung to the floor by some unknown force.
In the narration of Rhoda's dream, Hardy is careful to depict her as the wronged individual. Gertrude sits on Rhoda's chest and taunts her by flaunting her wedding ring. Rhoda acts in self-defense and within a dream, and so her hurting of Gertrude can't be attributed to actual malice. And at this point, outside the dream world, Gertrude is unaware even of Rhoda's existence, let alone that she has herself supplanted Rhoda's rightful place. All Gertrude has done is marry Lodge because she loves him. Both women are victims of a situation not of their making, and one they can't control. When they hurt each other, it is unknowingly and without volition. As Rhoda thinks to herself when she and Gertrude are on the way back from Conjurer Trendle's: "their lives had been antagonized by other influences than their own."