Arguing against myself: Gwendolen vs Rosamond

The other day I wrote that Gwendolen Harleth's basically Rosamond Vincy under different circumstances.
Now I'm revising that view. No, I'm arguing against myself. 
There's 1 crucial difference between these 2 characters: spoilt, egocentric, superficial, conceited and frivolous as Gwendolen is, she has a conscience and enough sensitivity to notice negative feelings (pain/ sadness/ anger/ resentment/ hurt, etc.) in people that she cares about (her mother especially), reflect on her actions and find herself in the wrong. One might argue that feeling bad about something isn't enough, because Gwendolen still marries Grandcourt despite knowing about Lydia Glasher, for example, but she does torment herself and is filled with shame and self-loathing. One might argue that earlier when she hurts her mother or her sister, she only makes it up through some gift or soothes them with words and some gentle gestures and doesn't change, and that's because she's a shallow and selfish person, who is used to behaving that way, but she does realise that she has been wrong and tries, in her way, to make her family member feel better. If a person has even a little capability of contemplating her actions and seeing her own errors, there is hope for improvement, George Eliot seems to argue, and there can be improvement only if a person finds herself in need of improvement, i.e. sees herself in the wrong. Rosamond is similar to Gwendolen in many aspects, but she always finds her conduct impeccable and irreproachable. In her mind, the blame always lies with someone else. Told of the rumours, she can only think of the disgrace and her own misery, and doesn't once ask herself why Lydgate accepts the 1000 pounds, doesn't once realise that it's her that drives him to that point of desperation and stupidity. 
What distinguishes Gwendolen from Rosamond is that the former can be ashamed of her own actions, whereas the latter's only ashamed of bad reputation and disgrace. 
Is this important? Yes. You can't talk about George Eliot without talking about ethics. The other day I was wondering about the narrator's partiality, about why George Eliot sides with Gwendolen but apparently doesn't side with Rosamond, but now I see the reasons. This important point about self-reflection and self-awareness and ability to find oneself wrong also, interestingly enough, makes George Eliot closer to Jane Austen than people think. Detractors of Mansfield Park, for instance, ask why Jane Austen disapproves of Mary Crawford, but if Elizabeth Bennet can think deeply about her judgement, realise her mistakes and learn from them, Mary lacks self-reflection, and isn't good at heart. 
2 writers, different if not opposing in many respects, ultimately make the same point about ethics.