The Fisherman's Widow and Mary Kelly.

Several images are suggested as the framed print The Fisherman's Widow that Mary Kelly hung above her fireplace (Miller’s Court).

I think it is:

The Fisherman's Widow by J.H. Burgers, shown in the Winter Exhibition at the French Gallery, 120, Pall Mall.

Original engravings and etchings were an expensive item in the Victorian era . It is unlikely Mary would have kept an object that would, if pawned, supply her with needed cash. Wood engravings were a cheap and cheerful mode of decoration for the labouring classes. 
The Fisherman's Widow, an image printed for The Illustrated London News, was published on the 5th December 1868, twenty years before her murder, probably in shabby condition, and worthless. The complete publication sold for 1d.

The title was shown beneath the print. Any journalist could, without any knowledge of fine art, embellish his story with that detail.

There is something in the image that is evocative of the Irish migration caused by the potato famine, which would resonate with Mary Kelly ...