There is an Ellen Maud Wills, also from Stokenham, around the same age in the 1881 Census, also in Slapton Village, that seemed like a good candidate at first, but trying to figure out her parentage turned into a hopeless muddle, so I have moved her information into this new answer. This abstract comes from Ancestry.com:
- William Tabb 26 head Ag Lab (born Slapton)
- Mary Ann Tabb 25 wife (born Stokenham)
- Ellen Maude Wills 4 step-daughter (born Stokenham)
- William John Tabb 1 son (born Slapton)
My initial search of the Slapton Primary School Admissions books, which otherwise have been an extremely rich source of data, came up empty. However, searching again for ALL children born around 1877, and looking at all the search results, I discovered entries for Ellen TABB (why these didn't turn up earlier when I searched for any child name Ellen, I can't explain).
The first entry:
(entry number) 257 admission date 21 May 83 Ellen Tabb (Wells) born 28
July 76, daughter of Mary Tabb, Slapton, achieved the standard for
first form (I) 23 May 84, exit date 13 Nov 85
The second entry:
re: 257 admission date 10 May 86 Ellen Tabb born 28 July 76 daughter
of Mary Tabb, Slapton -- last school attended Portlemouth, highest
standard there presented I, dates 23.5.84 (with superscript 1887), II.
1888; date of leaving is lined out
There is a William John Tabb (born 23 Mar 80), son of William Tabb, entering the primary school on 24 March 84 -- his exit date is 16 Jan 85. A second entry with the same student number is re: 279 admission 23 3 85 William Tabb born 26 3 80 parent William Tabb, Slapton (Here) exit date 6 11 85
There is a matching 1891 Census household in 1891 in East Portlemouth (RG12/1716/79/10) for which all the children born in 1885 or older are listed as having been born in Slapton; the younger three are born in Portlemouth. Ellen M Wills is not enumerated with this family.
(As I write this, neither Stokenham nor East Portlemouth are in the list of available towns in the search filter for the School Admissions Registers.)
So, to recap -- Ellen Tabb / Wills / Wells, stepdaughter of William Tabb, has a timeline that looks like this:
- 28 July 1876 (per school register) born in Stokenham (1881 census); this
agrees with date in her birth registration from 1878 Q3 Kingsbridge Vol 05b page 127 (I have a PDF copy of the entry from GRO pilot PDF program), which gives her birthplace as Frittiscombe, Stokenham)
- 3 April 1881 enumerated in Slapton (age 4)
- 21 May 1883 admitted to Slapton Primary School
- 23 May 1884 achieves standard I
- 13 Nov 1885 exit date from Slapton Primary School
- (?) attends school in Portlemouth
- 10 May 1886 re-admission to Slapton Primary School
- 1888 achieves standard II
- ??? exit date from school not shown (space in ledger is lined through with no entry underneath)
Other records which might be this Ellen Maud Wills:
- Birth registration for WILLS, ELLEN MAUD from Kingsbridge, Q3 1876 Volume 5b Page 8908a (Update: Ancestry's index is in error -- this is 5b 208a as listed above and on FreeBMD)
- Baptisms from Stokenham, archive reference 3031A/PR/1/5:
Baptised on 17 Nov 1878, Ellen Maud, daughter of Mary Wills of Stokenham.
What about a marriage record for her mother Mary? I went hunting for likely candidates and found:
From 3Q 1879, registered in Kingsbridge:
- TABB William Kingsbridge 5b 357
- WILLS Mary Elizabeth Kingsbridge 5b 357
From the Slapton parish registers:
This is problematic because it is Mary Elizabeth, not Mary Ann, and we have no clues about either Ellen Maud Wills' father or Mary Elizabeth Wills' father.
Possible census records for Stokenham for Mary Wills include a 1861 household (RG9/1423/86/3) at Chillington Cottage, Chillington, Stokenham headed by Abraham Wills aged 50. In addition to his wife Mary Ann, the household includes a son, three unmarried daughters, a granddaughter Mary Ann Wills aged 5 (calc 1856), and two boarders, one of the them with the surname Kellond (the same surname as one of the witnesses at William Tabb's marriage to Mary Elizabeth Wills in 1879).
In 1871 (RG10/2100/56/2), there is a Mary Wills age 14 (calc 1857) working as a servant in the household of William L Pitts aged 31 (calc 1840) -- one of the other people in this household is an Ann Cole aged 74 (calc 1797) whose relation to head is "wife's grandmother".
Many of these surnames are common in the South Hams, so I don't put too much significance on these coincidences, but I plan to follow up on them.
One possible answer comes from Wayne Shepheard's blog post, Don’t Forget About Those Half-Brothers and Sisters posted Tuesday, 13 January 2015, on his blog Discover Genealogy. Wayne is an Online Parish Clerk for four parishes in Devon. He says:
In many generations of my own family, there were family members who
shared only one parent with their siblings or, in some cases, were not
even related by blood to their “parents”. One of my great-grandmothers
had a daughter from her first marriage, before she married my
great-grandfather. My father considered her his aunt in the same way
he thought of her half-siblings, the natural daughters of both of his
grandparents. I have found similar circumstance in the many Devon
families I have investigated as an Online Parish Clerk.
This suggests to me that I need to broaden my search, and that there may be other connections farther back in the family than the generations I have looked at so far.
I searched for Ellen Maud Wills in the new GRO Online Searchable index and got the following result:
Name: WILLS, ELLEN MAUD mother's maiden name: -
GRO Reference: 1876 S Quarter in KINGSBRIDGE Volume 05B Page 208
Occasional Copy: A
... which ties in nicely with this related question: What does "Occasional Copy" refer to in the new GRO Index?
I then searched for the GRO reference that I had found on Ancestry:
- Name: Ellen Maud Wills
- Registration Year: 1876
- Registration Quarter: Jul-Aug-Sep
- Registration district: Kingsbridge
- Inferred County: Devon
- Volume: 5b
- Page: 8908a
Searching for this GRO Volume and page produces no results.
I searched for the surname, female, with no forenames or mother's maiden names, plus or minus 2 years from 1876. This produced no results. I also tried Wells and Tabb as surnames.
I then went back to Ancestry to check their image. The image clearly says page 208a so I have no idea how Ancestry's OCR got "8908a" out of that.
Note that there is no mother's maiden name given from the GRO reference. This seems to be in line with another person in my area of interest who is known to be illegitimate.
His birth registration reads:
ALLERY, WILLIAM JOHN (mother's maiden name - )
GRO Reference: 1857 M Quarter in KINGSBRIDGE Volume 05B Page 179
And in the 1861 Census (Piece 1422 / Folio 71 / Page number 17) where 4 year old William is listed as the son-in-law of the head of household, the enumerator has written 'illegitimate child' in the occupation field. William's mother Maria Allery, the housekeeper, is on the line immediately above.
The PDF of the birth registration from the GRO's pilot program has arrived: 
The information is consistent with the baptism record posted above (name of father / profession of father is blank).