Ellen Taylor 1812 & John Lester 1811

[Neale1961]

it is quite possible they were related somehow.
The Cartmale / Cartmeale name appears in Lichfield records as far back as late 1500s. The Lester/ Lyster surname is also attached to Litchfield from at least the early 1700s.
As you delve deeper into the roots of the family, you might find more connections.

[GillyT]

Looks possible at 1st glance without doing a proper check.
Sarah Cartmale's parents seem to be Richard Cartmale & Dorothy Shorthurst. They also had a son John.
Sarah had a daughter Mary Lester in 1779. John had a son William in 1782.
Seems that Mary and William share the same grandparents,  Richard & Dorothy.

[Neale1961]

Looks possible at 1st glance without doing a proper check.
Sarah Cartmale's parents seem to be Richard Cartmale & Dorothy Shorthurst. They also had a son John.
Sarah had a daughter Mary Lester in 1779. John had a son William in 1782.
Seems that Mary and William share the same grandparents,  Richard & Dorothy.

You are referring to this marriage
Marriage St Chad, Lichfield 30 Apr 1810
Mary LESTER to William CARTMALE
Witnesses - Catherine Lester, John Orton

I agree with you regarding Mary Lester - possibly the one born 1779 (Daughter of Thomas and Sarah)
Witness to the marriage was Catherine  - she will be Mary’s younger sister (born 1786)
John Orton could be husband of Elizabeth Lester .

If you look at this couple in the census and William’s death, William Cartmale is younger than his wife, it seems he is most likely -
William Cartmale born 1788 Lichfield (not 1782)  – son of John