Loving a puzzle.

That Jane Locklort/Tocklart - familysearch shows her in a Vail household from Germany (I'd actually doubt they are from Germany; the HOH's place of birth is blank, and the others dittos, Germany belonging to the previous household), with a Stokely couple from Pennsylvania, and one other young single woman, from Ireland. I would suspect they were both domestic servants.
https://familysearch.org/pal:/MM9.1.1/MC1C-9YJActually, and see, I am learning things, you can see the census image there. Once I adjust my javascript blocker ... it doesn't show an occupation or relationship for them, although they might be meant to be dittos to the Servant written after Mr. Stokeley's name. The Vails are the idle very rich.
Robert Lockhart 1834 is in the household of John Cloyde.
https://familysearch.org/pal:/MM9.1.1/MC1Z-PMHbut I cannot for the life of me get it to show me the image:
https://familysearch.org/pal:/MM9.3.1/TH-266-11861-24955-0?cc=1401638John Cloyde was born 1787 in Scotland, his wife Margaret 1790 in Scotland. They have three Dow toddlers with them, born in Newfoundland and New York, and a Mary Dow aged 31 born in Scotland. There is also a John Boyd aged 23 born in Scotland.
I can't get the image no matter whose name in the household I try it from. The pages before and after, yes; that one, no. Maybe someone could see it at Anc'y?
John Lockhart 1820 Scotland is a ropemaker.
https://familysearch.org/pal:/MM9.1.1/MC18-5YNI'm even wondering whether Robert c1834 might be a child of Ellen's from before marriage ...
In 1900 he is single, a lodger, with an assortment of people, in a white collar / artsy neighbourhood in New Orleans, and is a sexton! Year of immigration to the US (i.e. from Canada) seems to be 1836 (63 yrs in US, still an alien).
edit - got the 1850 image for him by switching to IE. John Cloyde, 63, born Scotland, upholsterer - as are Robert Lockhart aged 16 and John Boyd aged 23. Cloyde is just an odd name, and doesn't really seem to be a name. It's what it looks like, and Margaret Cloyde aged 90 died in Illinois in 1879, which is a match for the wife in the household. A spelling change on crossing the water, I would say, as those are the only occurrences of the name at familysearch. Clyde, as pronounced, maybe.
But I do wonder whether someone might have misread ... Crezie? Too much of a stretch, I think. Although ... it sometimes comes as Clazie, for instance?
Playing with the 1860 (because no image is available free), on the next census page (although possibly not - RH on page 14 is in Third Ward Memphis, Wm on page 15 is in Second Ward Memphis, both Shelby), family 98 (RH Lockhart is in family 91), is Wm Lockhart, aged 30, born Scotland c1830. They gotta be related. William born in Scotland c1830, Robert H born in Canada c1834, both in Memphis in 1860, Robert is in Troy in 1850.