PR entry of the marriage of Thomas and Elizabeth. (Top, right-hand page.)
http://www.lincstothepast.com/Records/RecordDisplayTranscript.aspx?oid=607313&iid=424908I would probably take a punt and say that Elizabeth is the widow of Charles, simply because that marriage took place in the city. On the other hand Burton-by-Lincoln is only a couple of miles outside of the city.
http://www.genuki.org.uk/big/eng/LIN/parishes.htmlYou can search many of the PRs online at
http://www.lincstothepast.com/but do read the 'help' section first and with the 'how to search for parish registers' do make sure that you read to the end so that you enter the correct parish name.
Enter the name followed by PAR 1 in the 'With the exact phrase' box.
Many registers prior to 1813 are classed as 'general registers' as they contain a mixture of baptisms, marriages, and burials.
This is the St Peter at Arches general register, and if you scroll down a bit it tells you which dates are applicable to which events, and some images have surnames transcribed.
Image 21 might prove interesting

though I would advise you to search at least the Burton-by-Lincoln register too.