I don't think it is the sister of Ellen that married James Rossiter. Louisa is 4yrs in 1881, his marriage was 1885. Louisa sister of Ellen married Fred Oaten in 1900
These look possibles
Deaths Mar 1916 Parsons George 65 Taunton 5c 428 (age is a few years out for age in 1901, so may not be yours)
Deaths Mar 1922 Parsons Flora 77 Taunton 5c 457
It would be useful to check MI's for West Monkton, this link states it has the approx 900 MI's for the area, it is pay to view but only a small amount per record, at least you can hopefully pinpoint your folk before you buy death certs.
http://www.familyhistoryonline.net/database/SDFHSMIfull.shtmlhttp://www.familyhistoryonline.net/database/index.shtml#SOMAlso Somerset Record Office hold details of burials
www.somerset.gov.uk/archives/ASP/parish.asp?Parish=West+Monkton You could contact them direct or post on the Somerset board, with a link to this thread, and ask if anyone is visiting the record office. There are also some look up offers (Taunton cemeteries) and resources on that board, worth checking, if you already have not.
Also post 1901 you could look at obituaries and wills to see if Ellen is mentioned. Possibly George or Flora have newspaper obits, are in the directories, or did wills if they ran the post office. The Library below has a email link and has a collection of newspapers & directories. If there are wills to be had at Nat Archives, Deb is a whiz at finding them...
The Somerset Studies Library is based at Taunton Library. It is a public reference library which holds a variety of local history material including books, journals, maps and illustrations. The Somerset Studies Library also offers a local family history research service.
http://www.rootschat.com/links/03gd/ Click 'contacts' at the bottom of service info, for email addie
Just a few possibles, good luck
Cas