Still nagging at me, would like to have more information of the following, only because the spelling of Thirlow is correct
Please
don't get hung up on spelling. In the early 19th century there was no such thing as 'correct' spelling. Just accept that there are several ways of spelling Th*rl*w, all of which are equally valid.
Thirlow Fraser born 20th May 1859 Tyrie, Aberdeenshire. Only lists the mother Margaret Fraser.
There is a Margaret Fraser Born Jan 1844 Skene, Aberdeen with a father named Findlay Fraser.
Coincidence that William Fraser's middle name is Findlay who married Isobel Mitchell?
Are they related?
Another excellent way to waste time is to speculate unnecessarily about possible relationships, especially when you are dealing with names as common as Fraser, Mitchell and Fin(d)lay. You know from the census that Margaret Fraser was born in Fraserburgh about 1838, so why speculate about someone born 5 or 6 years later than your Margaret, in a parish 40 miles distant, at the other side of the county from Fraserburgh, who would have been only 14 years old when Th*rl*w was conceived?
There is a very easy way to find out who Margaret Fraser's parents were. You know from the marriage certificate of her son Th*rl*w Dunlop that she married James Imlah, and from correspondence here that the marriage took place in Aberdeen in 1863. Go to Scotland's People and get that marriage certificate. It will tell you the full names of both parents of Margaret Fraser.
