1851 Census
Kilrhedyn, Cardiganshire
Thomas Marks, 51, Head, Mar, Farmer of 12 Acres, born Cilrhedyn, Carmarthenshire
Charlot Marks, 41, Wife, Mar
Anna Marks, 12, Daug
Ann Marks, 9, Daug
David Marks, 6, Son
Margret Marks, 2, Daug
1841 Census
Kilrhedyn, Cardiganshire
Thos Marks   40 Ag Lab
Charlote Marks   30
Elizabeth Marks   11
Mary Marks   5
Sarah Marks   5
John Marks   5
William Marks   4
Anna Marks   2 (likely Hannah)
GRO;
MARKS, MARGARET, Mothers maiden name DAVIES***  
GRO Reference: 1849  M Quarter in NEWCASTLE IN EMLYN  Volume 26  Page 737
So you think that Thomas may have been married Twice?
First to a Elizabeth?
1861 Census
Thomas Marks   60
Charlott Marks   50
Margaret Marks   13
James Marks   10
Jennet Marks   6  (likely Jane)
MARKS, JANE, mmn   DAVIES  
GRO Reference: 1855  J Quarter in NEWCASTLE IN EMLYN  Volume 11B  Page 19