Hi Margaret

Have found a possible on the 1851 Census but not on the 1841 for some reason.

1851 Hertford Heath, Hertford
Elizabeth Cowell Head Widow 66 Victualler b. Herts, Hertford
John Smith Visitor M 28 Waiter E.J.C. Inn b. Herts Gt Amwell
Phoebe Smith Visitor's wife 32 b. Herts Hertford
Sarah Salmons Servant 15 House Servant b. Herts Ware Side
Thomas Deards Visitor Unm. 24 Ag. Lab b. Herts Little Amwell
HO 107 1711 f 295 p 33

Also found these 2 references on Ancestry that may be useful:
Hertfordshire Register of Marriages 1569-1837
Marriages
The Parish Register - Volume 1
Volume 3
County: Hertfordshire
Country: England
Thomas Cowell & Elizabeth Taylor 12 Feb 1765

Hertfordshire: Great Amwell, Little Amwell - Parish Register & Tithing Book of Thomas Hassall
Marriages
1657
County: Hertford
Country: England
Thomas Cowell and Elizabeth Phillips were married the xxixth of June.

Will take another look at the 1841 and come back to you if I find anything.

Good luck
Pam