Debbie,
Before you try to use the Lincs to the Past website, do read the 'help' section, especially the part referring to parish registers. At the end of the PR section is a list of the correct names you need to search for parishes. e.g. the church in Spalding is spelt Nicolas, not Nicholas.
To find the registers, click 'advanced search', and then enter the parish name followed by PAR 1 in the 'with the exact phrase' box. Scroll down the list to find the register with the relevant event(s) and dates - prior to 1754 (possibly later) you will usually only find 'General register' which has baptisms, marriages and burials all lumped in together. Click on the thumbnail, and then work your way through the register. If there are a lot of images then you can often do some fairly accurate guesstimates on the image number you need. e.g. if you have 20 images covering baptisms 1820 -1840, and you want a baptism circa 1830 then start on image number 10 or 11.
Marriage of Samuel and Alice in Wrawby.
http://www.lincstothepast.com/Records/RecordDisplayTranscript.aspx?oid=551993&iid=126603South Kelsey marriages for 1846 have been transcribed on FreeREG.
http://freereg.rootsweb.com/Just search for marriage, Williamson, 1846, Lincolnshire and check the results. You'll soon find the one you (don't) want, and should realise your mistake.
Both churches in South Kelsey are well represented on FreeREG for the period you're looking at. (Check the 'counties and parishes coverage' link on the opening page.)
Edited to add:
If there are no siblings for Ann in South Kelsey, then just search for Williamson in Lincolnshire +/- so many years (Williamson is a fairly common name so it might be easier to search in blocks of just one or two years ) and then look for entries with Samuel as the father's name. Obviously then click on the link and see if the mother's name is Alice!
