A literary character who might be seen as a modern version of Mrs Harlowe is Stella Kowalski of Tennessee Williams' A Streetcar Named Desire ; Stella also yields on every point; it's easier; it's safer in a way; one mustn't make too much of these things she tells Blanche; she can't think of anything else (neither can Blanche; her idea of a shop is ludicrously unreal given the two women). The Harlowes' mistake is that they thought they had a Stella in Clarissa; not quite, or not a by a long shot, depending on your view of Clarissa's attraction to Lovelace.
I would add such a character does not have to be a woman; it is inadequate to see Richardson's moral pattern in Mrs Charlotte Harlowe as specifically or only about women; Trollope, for example, shows men being bullied into misbehaviors of various sorts which have bad consequences in a number of novels, e.g., The Claverings (by his family), poor Cousin Henry whom everyone dislikes because he is so unlikable (being craven); some, on the other hand, are deeply sympathetic, not so much because they defy or challenge the social order, but rather escape it, e.g., Mr Harding who manages by escaping late one night from his son-in-law (not an easy thing to do, requiring for example, hours of miserable wandering in London while waiting for a big man, a lawyer, to return from the law courts).
Perhaps someone would like to disagree. I do not agree with Prof Dussinger that the paradigm for Clarissa is finally the fairy tale, though I realize I would have to define fairy tale which I think of as child-like and unreal (but have no exact definition for) before I can really disagree. What always gets me about Richardson is how real it is; how he goes to the center of primal real experiences in adult lives.