Forfariain: I've had a good look at www.scotlandspeople.gov.uk , but I don't see an obvious link to search for early records, pre-1841.
The available pre-1855 baptism and marriage records are under 'Church registers'. There are almost no useful census records before 1841 because 1841 was the first year when they collected names rather than just numbers of people.
Can't even find 'Garve' in freecen...have put in fairly broad searches for both May Fraser, and
(blank)Fraser, Ross and Cromarty, have hunted the 1851 census. I don't get 'Garve' as an option for Ross and Cromarty?
My apologies, I see that I misled you. I typed that Garve is a parish when I should have typed that it is a village, and I typed 1851 when I intended to type 1881. Garve is a village in the parish of Contin.
I have downloaded the 1872 marriage certificate. It confirms that Lachlan's parents were Archibald Bell and Mary McTavish, and May's parents were William Fraser and Janet Fraser, maiden surname Ross. If you want a copy of it, send me a PM with your e-mail address.
William Fraser and Janet Ross had six recorded children
Christian, born 1829, Loth; Ann, born 1831, Forres; Elspet, born 1833, Forres; Georgina, born 1836, Forres; May, born 1838, Forres; David, born 1841, Tarbat.
There is a Fraser family in the 1841 census at Meikle Tarrel, Tarbat: William, 40, farmer; Jannet, 30; John, 13; Christian, 10; Eppy, 8; Georgenia, 5; May, 2. Janet was born in Ross and Cromarty but the birthplace of the others is 'unknown'. (There is a baptism of a John Fraser, father's name William, no mother's name stated, in Loth in 1828.) So I am reasonably confident that this is your May. However I have no idea why she said in 1881 that she was born in Garve. Or why she said she was 35 when she was only 32.
I've poked around with SP and Freecen, I find people on one that aren't on the other... For example, May Fraser aged 16, daughter of John and Mary. Urquhart and Logie Wester, on SP 1851 census doesn't appear on freecen 1851. Weird. I suspect freecen...
Go to the FreeCEN home page
https://freecen1.freecen.org.uk/ and click on 'Database coverage'. Click on 1851 and scroll down and you will see that only 13.5% of Ross and Cromarty has been transcribed so far by FreeCEN. Click on 'Details' and you will see that Urquhart and Logie Wester has not yet been transcribed, so that is why she is not listed on FreeCEN.