Hi... saw your query a while back somwhere, finally dug around a bit. First, in the 1880 Census, Ziba and crew got indexed with an "M", rather than a "W". Go to the Mormons' site (www.familysearch.com) and search all first names "Ziba" in RI in the 1880 Census. Strangely enough, there aren't many :-> Anyway, if you haven't see this b4... it should help, as it shows several other kids. The family is in Providence city:
Julia A. MARFIELDWifeMFemaleW34RI
William H. MARFIELDSonSMaleW15RI
Edith M. MARFIELDDauSFemaleW11RI
Celia Marion MARFIELDDauSFemaleW8
Anna E. MARFIELDDauSFemaleW7RI
Lester H. MARFIELDSonSMaleW4RI
Also, you mentioned how Ziba, Julia, Edith, Freddie and Jesse are all buried in a cemetery together in Greenville RI. Well, RI has apparently gotten together to make a list of every person if every cemetery there... see this webpage:
The code SM045 (where your ppl are) is GREENVILLE Cemetery in SMITHFIELD, which I gather you know already...
About Ziba's parentage... I can't actually CONFIRM who they are, but it has to be Samuel Vernon Warfield, b. 11 Apr 1810 (you mentioned Samuel B is listed as the father on the death cert. and B to V is pretty close ). His parents are Lewis C. Warfield, b. 30 Aug 1784, and his 1st wife, Mary Remington. Lewis's father was Samuel, b. 1757. His line is well traced... a little internet searching (worldconnect, Mormons, etc.) will tell you all you need to know. Beyond that, the Warfield line, is Elihu Jr, Elihu Sr., to the immgrant, John.
Besides the Samuel name matching what the death cert. says... Samuel V.'s father and uncle Lewis and Luther Warfield are the only Warfields in Northbridge in the 1830 Census. "Samuel V. Warfield" is the only Warfield in RI in the 1840 census. He's in Glocester (Gloucester?), RI. By 1850, "Zilia C. Warfield" (that's how it's indexed) is in Foster, RI, age 15, living with an Anna Bowen, age 62. Maybe that was his maternal grandma??? There's also a George B. Warfield, age 18, in Burrillville (didn't jot down who hes living with, just that he's not with other Warfields). A "Samuel Warfield", age 39, is in Fall River, MA, Bristol Co., with wife "Sarah A.", 35 (which isn't 'Celia', but maybe that was a nickname?), and children Abigail, 12, and Henry, 7. The 1860 MA census index shows "Samuel V. Warfield" still in Fall River... All in all, good circumstantial evidence.