Are you aware that your ancestor Richard Merchant Walker is the son of Caroline [Taylor] Walker, and not her brother Reuben, as you have postulated elsewhere?
Caroline never married. Reuben married Elizabeth Cooper 20/05/1877 Clapham Park St James, as a bachelor and they had at least two children, William born 1879 in Bobbing, Kent and Jane in 1881 in Borden, before Reuben's death in 1886.
Also, 'James' Walker 1833 on your tree is actually Jane Taylor Walker. In 1851 Jane Taylor Walker, unmarried Grandaughter, house servant,is living in the household of Richard Sharp, thatcher, born c1779 Borden kent, and Fanny, schoolmistress, born c1783 Stockbury kent, the parents of Jane's mother, Mary Ann Sharp, wife of John Taylor Walker.
(Richard Sharp/Sharpe and Fanny Greensted were married 8th Dec 1806 at Borden, They had several children, including Mary Ann, baptised 18th Dec 1808 at Borden)
John Taylor Walker and Mary Ann Sharpe were married 2nd Jun 1832 at Borden .
Jane Taylor Walker later returned to live in Chesnut St Borden in various censuses as 'widowed' Jane Bassett, often living with sisters Mary Ann or Emily, and in 1881 with her married brother Reuben but I cannot find a record of her marriage.
Jane's daughter, also known as Jane Bassett, is living with her grandparents John Taylor Walker and Mary Ann nee Sharpe in census 1871, along with her cousin [Richard] Merchant Walker.
Are you also aware that Richard Merchant Walker's two wives were sisters, both being daughters of Robert Gray/Grey and his wife Ann Osborne.? Eveline Maud Daisy Grey/Gray is recorded as 'Daisy' in census material with her parents in 1881/91which made her hard to find at first, but the dates fit and she has siblings in common with Alice Grey/Gray who appears in census 1861/71 also with the same parents Robert and Ann. Eveline's birth cert also confirms her parents were Robert and Ann.
Richard Merchant Walker and Alice Grey's daughter Alice Caroline Walker c1882-12/03/1932 married Richard Henry/Harry Cain 2 May 1905 Fulham All Saints and had several children.
You know of Richard and Eveline's descendants already I believe.