Hi again,
Your list of the couple's births:
Mary 31.7.1791 St Marylebone
Isabella 11.8.1793 "
Ann 8.2.1795 "
William 4.9.1796 St Pancras
Mary 28.2.1798 "
Thomas 12.2.1801 St George Hannover Square
Richard 20.3.1804 ""
Jane 15.2.1805 Chelsea.
George 7.5.1809 Clerkenwell St James
compares with what I see in the various trees (with dates of christenings):
Frances 21.4.1793 St Mary Le Strand (parents George & Mary image Findmypast) (died next year)
Henry 2.2 1795 ditto ditto Married Hannah Stickney, Banns St James Westminster (image Ancestry, no parents mentioned, might well be wrong person) 'drowned in maelstrom' (no date or source)
William 4.9.1796 St Pancras Old Church (Parents George & Mary, image on Ancestry) Married Susannah Stock Clerkenwell 1817 witness Mary Todd (son George schoolmaster, daughter Mary Emily m Joseph Bishop)
Mary Todd 28.2.1789 (ditto, ditto) died unm 1877 admin George Todd schoolmaster neph & Joseph Bishop
Griffith Todd (from other post) 1.5.1799 St George Hanover Square (George & Mary, FindMyPast) m 1822 Mary Parker (same church as Thomas' first marriage, same page of register, witness G Todd) then m 1863 Maria Stebbings (with whom he already had three children) him widower accountant, son
George Todd Stockbroker
Thomas Todd 12.2.1801 ditto, ditto, ditto marriages you already know about
Richard Todd 20.4.1804 ditto, ditto, ditto m 1827 Louise Parker, same church as Griffith & Thomas, witnesses Griffith & Mary Todd.
It is quite plain from this that Griffith, Thomas and Richard were brothers and sons of George the stockbroker, and that William and Mary were brother and sister (but not necessarily siblings of Griffith, Thomas and Richard). It also seems to me quite likely that Frances & Henry might have been children of George the linen draper, who lived in the Strand.
Then there are the children on your list, most of whom are not in the trees I have. Overall, it looks likely to me that two or more families have been mixed up, but, because of the recurrence of names and in particular the name Griffith Todd, that the two families were probably closely related.
I think I need to do more digging and see if I can identify family links to the other children that you mention, see how the linen draper/glazier family tree fits together and whether they were the same as the Henry/Mary who had a child Griffith Henry Todd (christened St Martins in the fields).
Any more insights would be very welcome.
Thanks again for your help.
Alan