I have a copy of the marriage parish entry for Mary Ann Bird as I am also researching (unsuccessfully!) this line.
Date of marriage: 28th August 1837 at the Parish Church in Newark.
Mary Ann Bird is described as being a spinster of full age no profession is listed.
George Cobb is described as a bachelor and a labourer. Both were resident in Newark.
Mary's father is given as William Bird, profession - labourer.
George's father was William Cobb, profession - Brewer
The marriage was witnessed by John Cobb and Christine Cobb.
None of the party were able to sign their names.
Not too many details although I have deduced from this that at this point in time William Bird was not deceased.
Hope this helps.
Tina