I consider NoDS a direct sequel to HoDS. As already mention, a quick reference was made to Elizabeth, stating that she had recently passed away, so take that as connecting it with the first movie. Interestingly, no mention is made of David, the only other member of the family to have survived. But regarding that, I make stuff up in my mind regarding inconsistencies. After the carnage of HoDS, David was sent away (maybe with Maggie and - gulp - Jeff to start aneew somewhere else. David would retain a big portion of the family wealth, while the rest passed onto the only other distant relative, Quentin, who inherited the estate when David had no intention of returning. So, after all the blood-letting, Elizabeth remained, living in isolation. Mrs. Johnson had also sought employment elsewhere, leaving a secondary Carlotta as the new housekeeper (she was the second-floor maid until then). David, with Elizabeth's blessing, moved away with Maggie and Jeff. When Elizabeth died, and with David not wanting anything more to do with Collinwood, enter Quentin, a distant cousin.
Gerard