Hi Again Lisa
Here is C81 details of Thomas YORKSTONE/Euphemia McCREA/McCREE, parents of the IGI Margaret born 1874 Haddington. You will see that the daughter Margaret is with them here. It
could still be that Margaret was listed twice - once with uncle Peter in Lincoln (where she actually was) and once with parents (where she was not, but they counted her in anyway either in error, or in mis-understanding that they should not state not-present children to the Census taker) - I have come across this more than once in Censii. What is interesting here is that Thomas' father is in the house.
Dwelling: Ayres Wynd
Census Place: Prestonpans, Haddington, Scotland
Source: FHL Film 0224027 GRO Ref Volume 718 EnumDist 4 Page 15
Marr Age Sex Birthplace
Thomas YORKSTON M 34 M Dunbar, Haddington, Scotland
Rel: Head
Occ: Maltman
Euphemia YORKSTON M 30 F Isle Of Skye, Inverness, Scotland
Rel: Wife
Occ: Maltmans Wife
Margaret YORKSTON 6 F Haddington, Haddington, Scotland
Rel: Daur
Occ: Scholar
John A. YORKSTON 4 M Haddington, Haddington, Scotland
Rel: Son
Daniel YORKSTON 2 M Prestonpans, Haddington, Scotland
Rel: Son
John YORKSTON W 68 M Innerwick, Haddington, Scotland
Rel: Father
Occ: Labourer
The other (I think more likely) scenario of course is that the Margaret with Peter in Lincolnshire is not the daughter of Thomas above :--as follows:--
There
is another Margaret YORKSTONE born 1873 on IGI: to Alexander YORKSTONE and Ann HAMILTON. This is probably the C81 family:
Dwelling: 4 Malvern Place
Census Place: Glasgow, Lanark, Scotland
Source: FHL Film 0203638 GRO Ref Volume 644-3 EnumDist 21 Page 17
Marr Age Sex Birthplace
Alexander YORKSTON M 39 M Larbert, Stirling, Scotland
Rel: Head
Occ: Carter
Ann YORKSTON M 36 F Glasgow, Lanark, Scotland
Rel: Wife
Agnes YORKSTON 13 F Glasgow, Lanark, Scotland
Rel: Daur
Occ: Millworker
Ann YORKSTON 12 F Glasgow, Lanark, Scotland
Rel: Daur
Occ: Scholar
Janet YORKSTON 10 F Glasgow, Lanark, Scotland
Rel: Daur
Occ: Scholar
Alexander YORKSTON 4 M Glasgow, Lanark, Scotland
Rel: Son
Isabella YORKSTON 1 F Glasgow, Lanark, Scotland
Rel: Daur
Their daughter Margaret, not present and assuming she was still living, would be abt 7 going on 8, at C81 time. It could be the age was given as 8 and misread as 6, and she was with her uncle Peter in Lincoln. Or that Uncle got it wrong

. Noting that Alexander above was born in Larbert Stirling (as was the Peter I found in 1846)
The Lanark location of the family also sort of ties in with the IGI Marriage 1871 in Blythswood Lanark of a Peter YORKSTON & Isabella BELL......I couldn't find that couple in C81 Scotland, lending more weight to the idea that it's them in Lincolnshire.
FREEBDM gives these Boston YORKSTON/E:
http://freebmd.rootsweb.com/cgi/search.plAlexander YORKSTON died Jun Qtr 1873
Annie Donaldson YORKSTONE born Sep Qtr 1886
Thomas Ramsay YORKSTONE born Sep Qtr 1883
Herbert YORKSTONE born & died Boston 1875 Jun Qtr.
May Isabel YORKSTONE married Dec Qtr 1905
The daughter Annie's middle name Donaldson is the maiden name of the mother of Peter YORKSTON born 1846 Larbert.
The IGI gives a number of children to the Alexander YORKSTON & Ann DONALDSON of Larbert Stirling besides a Peter & Alexander; another son was John Donaldson YORKSTONE: and this is likely him in C81:
Dwelling: 19 Rosemount St
Census Place: Glasgow, Lanark, Scotland
Source: FHL Film 0203639 GRO Ref Volume 644-3 EnumDist 50 Page 14
Marr Age Sex Birthplace
John YORKSTON M 36 M Larbert, Stirling, Scotland
Rel: Head
Occ: Painter
Ann YORKSTON M 33 F Govan, Lanark, Scotland
Rel: Wife
There is a good photo of Blue Street, Boston, Lincs here (last one on page)
http://www.bostonuk.com/gallery/neilwright/index4.htmCheers
Anne