The final realization that Annie is driven by practical considerations instead of wanting to strike a blow for the team is, I should think, what really drove a wedge between them. Oh, it's true that the stupid idiot saw Anne take him back and assume that she was weak and stupid and wanted to be humiliated more because that's just how French people are but it's closer to the truth to admit that there weren't really a lot of jobs for someone with Annie's lack of labor force world skills so it made no sense to untangle herself from Steve if that meant her and the kids going hungry.
Hell, even her upcoming decision to rush into corrective surgery on an infant has something practical behind it somewhere. She can foresee a life of misery and isolation for her child because of something that must be her fault because she must somehow have lost control and wanted to correct the results of whatever oversight resulted in Leah having extra fingers. Once the crisis ends, she realizes that it's not her fault but still, it's kinda more expensive to buy custom-made things so a panicky decision is actually a fairly sensible one after all because it makes it easier for them to live within Steve's means.