Hello,
Not sure if this is a help but I see 3 civil births registered to Samuel Knox and Elizabeth Downes:
1864 Male Knox, Coleraine Registration district
1866 No Name Knox Londonderry Urban No.1 district
1869 John Mason Knox Londonderry Urban No.1 district
Regards
PS. also found this death notice from the Londonderry Sentinel:
Downs Elizabeth 12-Jul-64
July 7, at 28 The Cedars, Purney, London, Elizabeth Downs,
mother of Mrs. Samuel Knox, Coleraine, after a lingering illness, in
the 70th year of her age.
Also from same paper:
Knox Son 27-May-59
May 18, at New Row, West, Coleraine, the wife of Mr. Samuel Knox, of
a son.
Knox Son 05-May-63 On the 28th April, at New Row, West Coleraine, the wife of Mr. S.
Knox, of a son.
Knox Son 06-Sep-64 On the 27th August, at New Row West, Coleraine, Mrs. Samuel Knox,
of a son.
Knox Son 08-May-66 May 3, at Crawford Square, Derry, the wife of Mr. Samuel Knox,
formerly of Coleraine, of a son.
----------------------------------------------------
Samuel Knox living in New Row, Coleraine, Solicitor in 1843 Street directory, possible connection?
Knox, Samuel, Son, & Sterling, Esqrs., Solicitors, New Row, Coleraine and 4 Blessington Street, Dublin.
also appears in the 1820 directory Attorney, New Row