Wow, I did a FHSsearch of just marriages for Hackney 1799 and the results 512...half that number would be 256 unknown spouses... ?? Bit of a nightmare for those hunting
re: marriage as Marlham, Claire had April 16, perhaps banns, you gave us April 23,( Of course I know you have the actual info as you had details) and FHS says Apr. 25
https://familysearch.org/ark:/61903/1:1:NK9B-SM6The FHS shows few early Marlham....A Thomas shows up in St Clement Danes Parish : Minutes of Parish Vestries 1763...then christenings of a George & a Thomas Marlham in the 1760s St .Clement Danes, Middlesex ( a George later a father in a christening, 1788 Lambeth Surrey)
also an Arthur Marlham or Marlam Gentleman of Bushey , Hertfordshire Will proven 28 February 1776 ( FHS has an Arthur married 1746 Westminster London)
A rare name...Probably badly spelled then or now.... 8 are listed with the Marlham spelling on the FreeBMD... very few as Marlam, Marlem. etc.
Tax Assessment Westminster, Middlesex
Thos Marlam 1754 1764 Vere Street
Anthony Marlam ( Marlham ) 1752 1755 Mount Street
Arthur Marlham 1755 1758 Mount Street .... in 1769 Green Street
and just for fun I must add this name
Catherine Merlwham 1841 Address: Wych Alley