I have had some trouble determining who my ancestor, David Graham's, parents are.
This is what I know about him: born 1791 in Glasgow, Lanarkshire, Scotland and died 3 March 1865, in Cadder, Lanarkshire, Scotland. He married a Janet. I don't know for sure her maiden name, it could have been Graham also or Bowman (another thing I am interested in confirming).
Anyway, some people seem to believe David's father was a John Graham born 1765 in Scotland, died 14 May 1811 in Horry, South Carolina and mother possibly a Margaret Daron. However, I have seen nothing to prove this and would love to know if it's true or not. I found it unlikely because David was born and died in Scotland, and I see nothing to show that he ever was in America like them but I guess you never know what happened in the time between. Also, when I looked at John's will I didn't see a David but I think John might have been with another woman at the time? Maybe, if David stayed in Scotland, they cut him out of the will?
You are right to be sceptical. Sad to say, the probability is that someone has come across someone born at about the right time and wrongly assumed that he is the right person. The evidence you have speaks against this. Never trust anything you find in an online family tree!
David Graham and Janet Graham seem to have had two recorded children, both baptised in Cadder, Lanarkshire: Elizabeth, 1816 and David, 1818. The 1851 census lists David Graham, 60; Janet Graham, 57; and David Graham, 32 in Auchengree, Chryston, parish of Cadder. All born in Cadder, by the way, not in Glasgow. (Note that the census
never gives a year of birth; it tells you how old the person said they were on census day. If Janet's age is accurate, she was born between 1 April 1793 and 30 March 1794, in other words, she is more likely to have been born in 1793 than in 1794 as suggested above). You can see a transcription of the census at
https://www.freecen.org.uk/cgi/search.pl and the original at
www.scotlandspeople.gov.uk.
The 1841 census lists at Auchingreea, Cadder, David Graham, 55; Janet Graham 50; Janet Graham, 25; David Graham, 20; and Margret Graham, 15. Also, separate from the family, Elizabeth Graham, 40. So it may be that David and Janet had other, unrecorded, children, and that Elizabeth aged 40 could have been a sister or sister-in-law of either David or Janet. Bear in mind that adults' ages in 1841 were supposed to be rounded down to the nearest 5 years, so they could all have been up to 4 years older than the ages listed in the census.
The Scotland's People index lists a death of Janet Graham, mother's maiden surname Bowman, in Cadder in 1857, and you have already been told about David's death certificate. (If Janet was 66 in 1857, this puts her birth date as some time in 1790 or 1791; therefore either her age in the census, or her age on her death certificate, is inaccurate.) A Janet Graham, daughter of William Graham and a Bowman, was baptised in Cadder on 30 November 1790, who could be your Janet Graham, and would answer your question about the Bowman surname.
Their death certificates will tell you the full names of both their parents including their mothers' maiden surnames.
There's a death of a John Bowman, aged 70, in Glasgow High Church in 1866. I would take a look at that death too, to see if he was a brother of Janet Graham. You never know. The death certificate will also tell you the name of his wife, if he was married, so you can look for his family too, if he is related.