No Name: is Magdalen’s struggle about ethics?

Several years ago, discussing No Name, Tom at Wuthering Expectations wrote this post about ethics: 
http://wutheringexpectations.blogspot.com/2012/09/the-roused-forces-of-evil-in-herself.html

“"Evil" seems awfully strong, and "ripening ground of the undeveloped Good" is ridiculous, although I too have been lazily accepting the governess’s ethics by describing Magdalen's motivation as "revenge."  What if, instead, she is righting an injustice?  In her mind, sometimes it's the one, sometimes the other, but still, Evil?” 

I agree. Big deal! 
The ridiculous part is that Miss Garth’s worry about good and evil in Magdalen comes right after they talk about the unjust situation, i.e. before Magdalen knows how she’s going to take revenge and try to get her money back, perhaps even before she makes up her mind to do it. 
Miss Garth’s concern about the forces of evil in Magdalen, at that point, is based on nothing. 
Tom wrote another post about ethics in No Name, this time Magdalen’s ethics: 
http://wutheringexpectations.blogspot.com/2012/09/you-forget-how-strong-i-am-she-said.html
The argument is that Magdalen wrestles with her conscience, fearing that “her carefully planned, entirely justified fraudulent marriage will be an evil act”, and the ethics in No Name is not the author’s, but Magdalen’s. Magdalen struggles with ethics. 
But does she? Is her struggle about ethics? 
I didn’t read the chapter (S.4, ch.13) that way. 

“By slow degrees her mind recovered its balance and she looked her position unflinchingly in the face. The vain hope that accident might defeat the very end for which, of her own free-will, she had ceaselessly plotted and toiled, vanished and left her; self-dissipated in its own weakness. She knew the true alternative, and faced it. On one side was the revolting ordeal of the marriage; on the other, the abandonment of her purpose. Was it too late to choose between the sacrifice of the purpose and the sacrifice of herself? Yes! too late. The backward path had closed behind her. Time that no wish could change, Time that no prayers could recall, had made her purpose a part of herself: once she had governed it; now it governed her. The more she shrank, the harder she struggled, the more mercilessly it drove her on. No other feeling in her was strong enough to master it—not even the horror that was maddening her—the horror of her marriage.” 

I read it more as fear of the marriage, repugnance for the future husband, and hesitation about sacrificing herself for a purpose. 
She later says: 

““Thousands of women marry for money,” she said. “Why shouldn’t I?”” 

Again, I don’t think it’s about the ethics of marrying for money, which “thousands of women” do, but about the prospect of marrying someone she despises like Noel Vanstone and pretending to like him. Earlier in the book, Wilkie Collins may not describe the seduction, but he lets readers see that Magdalen finds Noel Vanstone repulsive, and each time meeting him she feels sickened and needs fresh air afterwards and doesn’t want to see more of his face. Once she even decides to go away for a few days just to avoid Noel Vanstone. 
To marry him is indeed to sacrifice herself (imagine being intimate with that sickly, temperamental, stupid, and cruelly stingy Noel Vanstone, ew).
However, Magdalen would have to choose between the sacrifice of herself and the sacrifice of her purpose, but she seems to have chosen to live for the purpose, especially after Frank’s abandonment. She’s like Captain Ahab, and the family of Michael Vanstone and Noel Vanstone is her white whale.  
I wasn’t entirely serious there, but I wasn’t really joking either. 
Magdalen hopes for something to happen, some kind of accident, before the wedding, because she can’t choose. She doesn’t want to marry Noel Vanstone, so an accident would be a convenient way to stop the marriage without her having to intentionally give up her plan. 
Similarly, she wants to kill herself, because now she only lives for a purpose—the revenge, but deep down, she doesn’t want to do it. The man is disgusting. Death would end it all. No more doubt, no more pretence, no more suffering.
She already seems depressed, and in her mind, she has nothing else to live for. Death would end it all. 
When the chapter is read this way, that Magdalen’s struggle is not about ethics, I have to think about the question of ethics in No Name differently.