When she realized that Andre wanted to brainwash her, it was like a switch got flipped; she stopped caring about him altogether. She was still upset, but more from the reveal that she used to be so awful not even her own father wanted her for who she was. She felt she was better as she now was, so it was for the good of everyone that she stay as she is now, no matter what.
It could tie neatly into her rapidly escalating mental health issues post-brainwashing that her lack of housewife skills causes her to have mental breakdowns at even the most mild of failure, as her conditioned NEED to be a good wife for Marinette combines with her pre-existing self-hatred and disgust of failure. Anything less then perfection is unacceptable
but good wives don't pester other people, they keep nice and quiet about their problems because why bother the nice folks about something as unimportant as their own feelings? When Tom and Sabine, who are currently stuck watching her for the day, notice how she's basically working herself to death just to be somewhat capable at housework, they offer to help; Chloe recoils the thought of "the man of the house" doing "wife's work," but when Sabine offers, she calms down and tearfully accepts, sobbing into Sabine's shirt that she's sorry she's such a bad wife to their daughter.
Adrien probably tries to get Sabrina on board, since Sabrina is the only other person upset about Chloe's change in attitude (albeit mostly because she thinks Chloe abandoned her to hang out with Marinette), while Alya, after being given Marinette's notes on what she's been able to figure out so far, investigates what "the Stepford Project" was... and when she dives into it, she immediately sounds the alarm to the cops about Andre, since she's convinced that it's him who did this.
Andre thought it would be some kind of subliminal messaging device or the like, something that would gradually "adjust" Chloe's bad attitude into something more... PR friendly. Chloe, on the other hand, just thought it would temporarily scramble Marinette's brain and make her embarrass herself in public (if she knew what it REALLY did, she'd have immediately backed out; even she's got some limits). What makes things even worse for Andre is that he was offered the one meant to be used on partners, not kids, and since that is the one Chloe found and bought, the image it paints for investigators even WORSE; bad enough he was trying to use brainwashing tech on his own kid, but tech meant to turn his kid into a housewife!? Yeah... that's going to get him DOUBLE trouble.
Twisted thought; when Chloe starts to realize her brainwashing is breaking after a moment where she has a negative thought about Marinette, and proceeds to have another breakdown, Audrey steps in, and comforts her. In addition to Chloe being shocked that Audrey remembers her name (compounded by her mommy issues coming screaming back in place as a side effect), Audrey tells her how proud she is that Chloe is finally doing something good for the family, and that she doesn't need to worry, because Audrey will ensure she becomes the perfect wife for the future Mrs. Marinette Bourgeois.
Audrey then begins using her connections to track down more Stepford Tech, and hiring scientists to modify it so that it'll brainwash Chloe into the perfect housewfie for Marinette... and a second device meant to brainwash Marinette into becoming the perfect "husband" for Chloe. Chloe has no clue that her mother intends to brainwash Marinette, she's too busy sobbing in joy that her mother is going to "fix her," and make her "perfect" for Marinette.
Whenever someone questions Chloe on why she calls Marinette her husband, Chloe, whose mind had to fill in the gaps the faulty brainwashing left behind, replies that silly little things like gender labels mean nothing when Marinette is obviously an ideal husband. She's talented, resourceful, well-connected, and is guaranteed a bright, successful future that will bring in the money that their family needs, meaning Chloe is obviously meant to be her devoted housewife, ensuring she never has to waste time doing silly things like cleaning, cooking, or washing clothes, not when Chloe can take care of everything for her.
Yup. Although it'd be perfectly in character for Gabe to think that Chloe got the brainwashing tech in the hopes that it would make him reconsider a future between her and Adrien, and laughs at how pathetic she is. When he learns that she accidentally brainwashed herself into loving Marinette, he'd probably order Lila to do all she can to ensure the brainwashing stays in place, and to see if she can have Marinette brainwashed as well; after all, Marinette can't be a bad influence on his son if she's too busy being a lovesick fool for Chloe Bourgeois. And if/when Adrien starts trying to buck Gabe's control, well... he'd probably be the type to look into brainwashing tech if it meant ensuring that his son "realized his father knew best."
For an extra splash of irony, the Sentimonster reflects Chloe's own warped understanding of the 1950's; which in this case means reshaping the world to be one where her being Marinette's wife isn't a problem. Couples all over Paris are arbitrarily separated into "dominant" partners and "submissive" partners, with Chloe happily falling into the "submissive" role even as she has the power to set herself up as Queen. Heck, she probably still does place herself as Queen... with Marinette as her aggressive, confident, "King." Anyone not effected by the change is probably gonna be shocked to see Rose swaggering around in a pink business suit, Juleka in a black and purple sundress fawning over her (Rose became the "Husband" between the two of them, with Juleka becoming Rose's "wife").
