Hi Nina
I haven't looked further but think you could have found a very good clue!!
These are the families you refer to.....
Dwelling: No 5 Sth Pettigrew Str
Census Place: Glasgow, Lanark, Scotland
Source: FHL Film 0203646 GRO Ref Volume 644-5 EnumDist 37 Page 3
Marr Age Sex Birthplace
John DOCHERTY M 39 M Glasgow, Lanark, Scotland
Rel: Head
Occ: Whitewasher
Jane DOCHERTY M 38 F Glasgow, Lanark, Scotland
Rel: Wife
Mary MC GOLPN U 38 F Ayr, Ayr, Scotland
Rel: Boarder
Occ: Cotton & Wool Winder
Dwelling: No 4 Sth Pettigrew St
Census Place: Glasgow, Lanark, Scotland
Source: FHL Film 0203646 GRO Ref Volume 644-5 EnumDist 37 Page 7
Marr Age Sex Birthplace
Mary DAVIE W 30 F Glasgow, Lanark, Scotland
Rel: Head
Occ: Shirt Finisher
Robert STEAD U 25 M Glasgow, Lanark, Scotland
Rel: Visitor
Occ: Hammerman
Ann DOCHERTY U 33 F Glasgow, Lanark, Scotland
Rel: Boarder
Occ: Weaver
and now here is your Margaret mn Watson household in 1881....
Dwelling: 2 Harannah St
Census Place: Glasgow, Lanark, Scotland
Source: FHL Film 0203646 GRO Ref Volume 644-5 EnumDist 39 Page 12
Marr Age Sex Birthplace
Margaret DOCHERTY W 58 F Glasgow, Lanark, Scotland
Rel: Head
Occ: Shawl Fringer
Jane DOCHERTY U 31 F Glasgow, Lanark, Scotland
Rel: Dau
Occ: Shawl Fringer
John DOCHERTY U 28 M Glasgow, Lanark, Scotland
Rel: Son
Occ: Carter
Patrick MC GIVIN 12 M Glasgow, Lanark, Scotland
Rel: Grandson
Occ: Scholar
Margaret ... 3 F Glasgow, Lanark, Scotland
Rel: Grand Daughter
Peter MC MANUS U 28 M Glasgow, Lanark, Scotland
Rel: Boarder
Occ: Bricklayers Laborer
now because you've found a married couple (though would be much easier if they had a wee one still at home with them) you can search for possible John/Jane combinations having Docherty children in Glasgow around 1858-1865 for instance. Not knowing of course if this particular couple did have any children but let's just assume they did. The IGI shows a possible John Dougherty/Jane Kennnedy that might be worth following up....they had these children recorded:
1. JAMES DOUGHERTY - International Genealogical Index
Gender: Male Birth: 22 MAR 1856 Central District, Glasgow, Lanark, Scotland
2. ROBERT DOUGHERTY - International Genealogical Index
Gender: Male Birth: 09 SEP 1858 Anderston, Glasgow, Lanark, Scotland
3. ROBERT DOUGHERTY - International Genealogical Index
Gender: Male Birth: 21 JUL 1861 Calton, Glasgow, Lanark, Scotland
Now I'm
not saying this is your family but you can see how I went about this. From this point you've now proven that this couple lived in likely areas...was born in Glasgow.....so likely married there. With the first birth the IGI shows being in 1856 they might have married in 1855...so worth checking the IGI for a marriage. So off we go.....and here we have....
JOHN DOCHERTY
Male Family
------------------------------------------------------------------------------
Marriages:
Spouse: JANE KENNEDY Family
Marriage: 16 SEP 1853 Glasgow, Lanark, Scotland
Too bad....they beat the 1855 magical year. But good because you now see that the surname was spelled DOCHERTY instead of the Dougherty used later so even more possible of a connection! Unfortunately what you really want is to get backwards another generation and find parents names. Since the marriage is in the OPR you could have this checked at NRH in case the banns states any parents names.....but the odds aren't good it will. The only other thing to try is to locate their deaths. You might need to look for Jane's first as you have two surnames for her. If that is found then you can narrow up a smaller death window for John. Then if you get really lucky and find John's death and it states who his parents were and if his father's name was William or John you have a possible chance he's a grandson of James Docherty and Sarah Boag. Can't prove that unless both his parents are named on his DC and hopefully the parents wll have died post 1855.
Lot of if's in my sample run around but not impossible to strike it rich.
Don't forget too that it might be possible to find a clue in the census....especially since this John/Jane couple have a baby in 1861 Calton that year might be easy to find. See if they had other children. See who else they could be living with.
Again lot of if's.............
Hope in some ridiculous way this helps

!
Best wishes
Jean