What was the timeline of the death of the real parrents of Arnold and Willis on the show? Didnt the day pass away first. How long after their mom died did they come to live with Mr Drumond? Was it ever said how they died so young?

When Arnold and Willis' mom was working as a maid for Mr. Drummond she was already a single Mom so Dad must have already been out of the picture. Since Mr. D had promised her he would take care of her boys in the event anything happened to her they moved in almost immediately after their mothers passing.

I would assume she had been termanly ill giving her for awhile giving her chance to make her wishes on to MR D I with they could have shown a flashback with the real parents.