Jane Eyre: Know thy context or be conned by the text

I noticed that the newest film adaptation of Charlotte Bronte’s Jane Eyre has been rated PG-13 for its “chaste passion” and “discreet violence”.

Additionally, Jane is marketed as a "mousy governess" on the poster.

I understand the commingling of passion with chastity—for the heroine, Jane, is an embodiment of chastity (i.e. she will be kissed by nor open her legs to anybody) which tempers the passion she develops over time for her beau, the Earl of Rochester. 

What I don’t quite get is the reference to the “discreet violence”. Does this refer to the burning alive of Bertha Mason, Rochester’s West Indian wife, who is neglected by her husband once he brings her over to England? He enjoys her estate, gets rich off her, and then conveniently decides that she is mad and confines her to the attic of her house.

If the quarantining and subsequent death of Bertha Mason is emblematic of violence that's "discreet", then the whole history of colonial violence, the substructure, upon which the superstructure of 19th century British prosperity lay, is discreet. 

But was this violence inflicted discreetly? Hell no; it was as overtly inflicted as is the modern day violence of a Ray Rice on his fiancee. The choice of the adjective "discreet" could be attributed to the race of the colonial master vis-a-vis the race of the servant subjugated by the former with impunity, back in those days. 

Bertha Mason’s treatment, we know today, is a direct consequence of her race—she was black. 

In the novel, Bertha hardly speaks; she is never seen. Only when the Rochester abode (which is refurbished with wealth from Mason's ancestral sugarcane plantation in Antigua) is up in flames, do we know that the madwoman in the attic is responsible for the arson.

Once the context is read into the novel, the violence done to Bertha hardly remains “discreet”.

Oh, and Jane can by no means be described as "mousy" (the film's poster sums up Jane's journey as a journey of increasing self-confidence). Her reticence is not a sign of her feminine diffidence; it's a pre-Victorian virtue, a virtue that would have been commendable in a young woman back then.

Context matters, else Jane Eyre would belong to the same category of fiction as The Nanny Diaries.