There is a Marcella Danby Symondson listed in the July to September 1841 birth index Pancras district London, Middlesex volume 1 page 265.

Listed in the 1851 census Address 3 Dean Street Civil parish Westminster St Margaret, ecclesiastical parish Westminster, Middlesex, England. Registration District Westminster, sub registration district St Margaret.
Theresa Symondson (or Symonson) widow, head, stationer, age 51, born in London. Son Henry Symondson age 18, born in London, occupation Music Seller.
Son Frederick Symondson age 17, born London, occupation Music Seller.
Daughter Therese Symondson, age 13, scholar, born London.
Daughter Marcella Symondson, age 9, scholar, born London.
[3 other families lived at this address as well, presumably on different floors.There are 5 floors today. I imagine their shop was on the ground floor and they lived above.]
[3 Dean Street is now a Tesco Store with address 2 to 4 Dean Street. Near Oxford Street.]
[Historical Note: Karl Marx (listed as Charles Mark) and his family were living at 28 Dean Street from 1851 to 1856]


parish records St Pancras Church
January 3, 1859
Sidney Francis Smith, full, age, bachelor, Artist, Albert Street, father Alfred Smith, Surgeon
Marcella Agness Symondson, Minor, Spinster, Carlton Terrace, father Henry Symondson, dead
in the presence of John Tordoff? and Teresa Danby Symondson [mother of Marcella]

In the 1871 census 45 Gloucester Street, St. George the Martyr, Holborn, London.
Head Catherine Phillips, unmarried, age 68, no profession, St. Martin’s Shand?.
Head Agnes Smith [can’t decipher condition, possibly widow], age 29, mantle maker, born St. Pancras.
Daughter Teresa Smith, age 12, born St. Pancras.
Daughter Mary S. Smith, age 10, born St. Pancras.

In the 1881 census 46 Gloucester St, St George Martyr, Holborn, London.
Mother Marcella Smith, [possibly listed as widow], age 38, dress and mantle maker, born St. Pancras, Middlesex.
Daughter Teresa Smith, unmarried, age 22, machinist, born St. Pancras.
Daughter Mary S. Smith, unmarried, age 20, assistant perfumer, born St. Pancras.
Aunt Catherine Philips, unmarried age 79, born in Erith, an annuitant.
Visitor Claud Symondson, age 19, born St. Pancras, Middlesex, barristers clerk.

In the 1891 census civil parish of Islesworth, ecclesiatical parish St Stephens, Middlesex staying at or living with son in law’s 3 Lorne? Villas, Hibernia? Rd.
William H. Morris, head, age 32 Spectacles? Makers ???, born London.
Wife Teresa C. Morris, age 31, born Kentish Town.
Daughter Marcella M. Morris age 7, born St Pancras.
Daughter Teresa F. Morris age 2 born ???.
Mother in law Marcella Smith, married, age 49, born Hamptead.
Sister in Law, Mary S. Scrimshaw married, age 30, born St. Pancras.
Niece Mary T. Scrimshaw age 5, born ???.
Nephew Sidney K? Scrimshaw age 2.
Nephew Edward Scrimshaw age 1.
Nephew Herbert Scrimshaw age 5 months.
Nephew Arthur Hudson age 19, Taylor.

In the 1901 census living at 25 Union Road Islington civil parish, St George ecclesiastical parish, London, Islington district, Upper Holloway subdistrict
Head Edward Scrimshaw, age 40, printers machine foreman, worker, born Middlesex.
Wife Mary S. Scrimshaw, age 38, born St. Pancras, London
Daughter Mary T. Scrimshaw, single, age 15, born Levington, Surrey.
Son Sidney H. Scrimshaw, single, age 12, born Levington, Surrey.
Son Edward F. Scrimshaw, age 11, born St. Pancras, London
Son Herbert Scrimshaw, age 10, born St. Pancras, London.
Son Frederick Scrimshaw, age 9, born Islington, London
Daughter Marcella C. Scrimshaw, age 7, born Islington
Son Horace G. Scrimshaw, age 5, born Islington
Boarder Marcella Smith, widow, age 56, living on own means, born St. Pancras, London
Boarder George L. Symondson, single, age 31, Civil Service Somerset House, worker, born St. Pancras
Boarder Horace D. Symondson, single, age 25, civil service post office sorter, worker, born St. Pancras
Boarder Ernest Hudson, single, age 26, civil service, worker, born St. Pancras
Daughter Martha E. Tearall, single, age 31, drapers assistant, worker, born Lenham?, Kent
Daughter Frances E. Tearall, single, age 23, dressmaker, worker, born Tunbridge Wells, Kent.
Son Ernest S. Tearall, single, age 25, Railway Engine cleaner, worker, born Tunbridge Wells
Son Thomas E. Tearall, single, age 21, clerk commercial, worker, born St. Pancras, London.
[Mary S. Scrimshaw is Marcella Smith’s daughter. Thus the other Scrimshaws are Marcella’s son in law and grandchildren. George and Horace Symondson are Marcella’s nephews, sons of her brother Frederick Thomas Symondson. Later this year Ernest Hudson will marry Marcella’s niece Kate Marcella Symondson, sister to George and Horace. In 1906 Frances E. Tearall will marry Horace Symondon. Martha, Ernest and Thomas Tearall are Frances’s siblings.]

In the 1911 census 25 Union Road, Tufnell Park, London , Islington district, Tufnell sub district.
Head, Edward Scrimshaw, married, age 51, printer, born Middlesex.
Wife Mary Scrimshaw, married 26 years, age 50, born Middlesex.
Daughter Mary Scrimshaw, single, age 25, commercial clerk, born Surrey.
Son Sidney Scrimshaw, single, age 23, commercial clerk, born Surrey.
Son Edward Scrimshaw, single, age 21, government clerk, born Middlesex.
Son Herbert Scrimshaw, single, age 20, law clerk, born Middlesex.
Son Frederick Scrimshaw, single, age 19, law clerk, born Middlesex.
Daughter Marcella Scrimshaw, age 17, commercial clerk, born Middlesex.
Son Horace Scrimshaw, age 15, school, born Middlesex.
Son William Scrimshaw, age 9, school, born Middlesex.
Wife’s mother Marcella Smith, widow, age 69, born Middlesex.

In the July to September 1927 death index Marcella Smith, age 86, Hendon, Middlesex, volume 3a, page 286.

Artist

A possible match. In the January to March 1861 death index Sidney Francis Smith, Pancras, London, volume 1b, page 100.