Hi Lockhaven
The possible death entry that Rosie mentioned earlier for Helen Lawson holds the clues in part to some of the names. The reason that Helen Lawson and daughter (Elizabeth it seems at 3 months old) was with the McLeans is that Helen Adamson looks to be her mother.
On Helen's death entry in 1893 at the age of 84, her parents are given as a David Lawson and Helen Adamson. See a clip below:
Thanks so much Monica, after I posted I purchased Helen's death cert. from SP. I didn't even catch that 'Helen Adamson' was listed on the 1841 census, thanks for that! It looks to me like Helen Adamson & Charles McLean got married (or didn't, since I can't find their marriage cert.) and had at least 3 kids together. That's where the McLean name comes in to play. I still haven't found 'David Lawson' anywhere. He must have passed away early on is my guess, before any of the censuses.
I think I may have found a William Crawford. He's listed in Markinch in 1841 with a John Adamson which is interesting being the same last name as Helen's mother, maybe Helen's cousin? And then, if it's the same William, born in Burnlesland, fifeshire, and I have him marrying a Margaret Nicol in 1845 and having 7 kids. It also shows him working as a Ploughman, which lines up with Elizabeth's Death Cert. So hopefully that's the right William Crawford, but it seemed to be the only ploughman William Crawford in Fife, so I'll go with that.