Interesting theory, but I disagree. I think the movie did a great job of showing how ironic it was that Rose lashed out at people trying to look after her when they didn’t believe her side of the story. In the beginning of the film, the shoe was on the other foot and Rose was yelled at for “not listening to” the first victim we see, while Rose was trying to comfort her.

From the fiancés perspective give, Rose killed their cat, boxed it up, and gave it to their nephew… and yet rather than immediately calling the police, he had the empathy to call Rose’s therapist to try and help her. At which point Rose lashed out again.

I don’t think their relationship is perfect but to me it was clear the filmmakers were intentional about showing Rose aggressively rejecting offers of help, just as Rose’s patients often do.