Have been puzzling over all this and think I might have it figures out (well nearly figured out as some certificates don't seem to be on N.S. Vital records website). The key to it is Finlay Cluney/Dawson. This is how I think it goes-
1) Thomas Cluney and wife Bridget McCoy have a large family, including Sarah (c1849) and Thomas (c1841).
- if this is the Bridget who died in Halifax 1900 there are several problems on death certificate (age 59 but listed as single and from St. John Nfld.).
- 1871 Census a son named Finlay is listed (more on him in a minute)
2) Thomas Cluney, son of Thomas Cluney and Bridget McCoy married 1875 Sarah Kate/C. Bennett (c1855-1927).
-In 1881 Thomas' household consists of wife Sarah, sons James and Angus, and his father Thomas (married). Thomas Sr.'s wife Bridget is in Dawson household
-In 1901 Census there's Thomas and Sarah with sons James and Angus plus 4 sons born 1882-1894
-In 1911 Census there's Thomas and wife Sarah with 4 sons
3) George Dawson (born 1840 England died 1931) and wife Christina died 1927.
-In 1881 George Dawson is listed with a wife Sarah, son Finlay 11, son James 10, son Charles 4, daughter Ada 1, as well as Bridget Cluney and 5 of her children. Notice that 'Finlay Dawson' is the same age as 'Finlay Cluney' from 1871 census.
-In 1901 Census George Dawson now has wife Christie, daughter Ada and an adopted daughter Ida M. McCarthy age 9.
-In 1911 Census George and wife Christie have an adopted son Alexander.
So, George Dawson and Sarah Cluney (born c1849, daughter of Thomas and Bridget) either married or living as man and wife are together in 1881 with Charles and Ada possibly children they had together. Finlay and James are most likely children Sarah had earlier.
By 1901 George is now living with 'wife' Christina McDonald and an adopted daughter called Ida M. McCarthy. Death certificate for Ida May McCarthy 17 Apr.1910 (age 19) shows she died from burns and shock.
At the time of the next census in 1911 George and Christie have another adopted child- Alexander born Dec.1907 who accidentally drowns in 1924. Alexander's death certificate (indexed as Danson) givesn his father as William Chapel (born Sherbrooke) and Ida Dawson (born Sheet Harbour)- George Dawson's adopted daughter. After Ida died in 1910 George and Christie must have raised her son as their own child.
There are several certificates I've not been able to find including a marriage for George Dawson to Christina McDonald.