I think I can confirm and add a bit to the Smeed tree:
I have a Susan Smeed Buzar who married into my DENNING Family:
Susan Smeed BUZAR & Thomas Henry DENNING (b Bristol 1820), married Bethnal Green Dec Q 1850 vol 2 Page 59 (FreeBMD)
CENSUS:
1841: ?
1851 aged 29 b Ramsgate Dressmaker - with husband Thomas - Platt St St Pancras.
1871 St Mary le Stand Covent Garden - 4 children
1881 7 Wakefield St St Pancras MDX
1891: ?
1901: living as widow on own means with son Alfred and his wife 36 Crossley St, Islington
1904: Susan DENNING aged 78 died Dec Q Islington - probably Crossley Street.
I have Susan as the daughter of William BUZAR and Mary Ann SMEED. whom as you say, married March 11 1817 St Lawrence in Thanet, Kent.
CHILDREN: All Bap St Lawrence in Thanet Kent
William Smeed BUZAR christening: 14 February 1819 St. Lawrence, Kent, England
Died: Jan Q 1842 Bethnal Green ref Vol 2 Page 30.
John BUZAR christening: 5 August 1821 St. Lawrence, Kent, England
Susan Smeed BUZAR christening: 26 October 1823 St. Lawrence, Kent, England
Mary Ann BUZAR christening: 4 March 1827 St. Lawrence, Kent, England
Not exhaustive list - there may be other children born)
Confusingly, there is another Susan Smeed Buzar born 1876 in Gloucester who married in Poplar in 1896 - I feel her father and William must be related somehow for both Susan's to have the middle Smeed name, but I haven't figured that one out yet
!
I wouldn't be too worried that some carried the middle name Smeed while others didn't, exactly the same thing happened in the Denning side where some used middle name Riddle and others didn't.
I assume Elizabeth Smeed who married John Black Mary Ann's sister. I have found a William SMEED b 1750 died 1824 aged 74 BURIAL: March 19 St Peter Sandwich Kent - looks like a good candidate for Mary and Elizabeth's father.....