For example, Pauline's infant sister, Rosemary, who was born with severe Downs' syndrome when Pauline was 11, was not shown in the film. Rosemary was finally institutionalized in 1951 or '52 and she is discussed in section 126.96.36.199. Herbert Rieper testfied that Rosemary was visited regularly and brought home from time to time. It's possible that Rosemary was a severe burden on the family in general, and on Pauline in particular, in the years she spent at home, although it was reported that Pauline was extremely fond of Rosemary. Rosemary, and the financial burden and responsibilities and demands of her care, could have been an extremely potent source of tension between mother and daughter, and she was omitted from the film.
The degree of poverty in the family was probably not portrayed to anywhere near the extent that the real-life Pauline would have perceived it. The family was literally living on the edge of solvency most of the time and money issues would have been a neverending source of concern and serious conflict. Every little expense Pauline would have wanted to incur, especially if it was to keep up with Juliet in some way, would have been the source of a family fight.
To an adolescent particularly, the accumulated effect of being left out of social events and not belonging because of lack of money is galling: how many parents have heard "it isn't fair" from their teenagers, refused permission to do something or buy something because the resources weren't there? No doubt Honora heard it day in and day out from Pauline.
There was evidence in trial testimony that Pauline hid significant expenses from her parents; for instance, she bought a horse without her parents' knowledge (Juliet had one...) although this isn't shown in the film. Herbert Rieper testified he relented and allowed her to keep the horse, thinking it would distract Pauline from her friendship with Juliet but obviously there must have been a huge explosion when he and Honora first found out about this horse. Remember, trial testimony among other things made it very clear that Honora was the disciplinarian in the Rieper home.
And class issues, though presented reasonably well in the film, were probably far more exaggerated and significant in the real-life Rieper household, especially because Honora was actually born in England herself and would have been steeped in British class consciousness. The amount of class tension between the working-class Riepers and the well-to-do Hulmes would have been palpable in most of their dealings with each other.
It wouldn't stretch the bounds of reason to imagine that vicious working-class cynicism and contempt could have been directed quite maliciously and relentlessly at Pauline. Especially if it was perceived that she was trying to rise above her station in life. And that contempt would have come principally from Pauline's working-class family, especially if their lives were inconvenienced by Pauline's shirking her family duties in the frivolous pursuit of 'bettering' herself with the Hulmes. Just by default, there would have been a huge amount of resentment of the Hulmes by the Riepers, and no doubt Pauline became a very convenient surrogate target for the Riepers' bile.
In particular, the role of Walter Perry in the whole story was much greater than shown in the North American version of the film, although it appears as if many of these issues were included in the Wellington premiere version of the film.
And, of course, most of the dynamics within the crumbling Hulme family weren't portrayed in the film, since the filmmakers chose to portray the story consistently from Pauline's perspective. This was probably a wise choice, artistically, because it gave the film a self-consistent and very compelling voice, and it was certainly true that most of the direct physical evidence presented at trial concerned Pauline and her thoughts and attitudes. Still, it may have led to a distorted perception of the Hulmes by audiences. And, it may have led to the minimization of elements which were very important ones as far as the motives for the real-life crime are concerned.