Excerpt from the minutes of the Glenbervie Kirk Session.
7 March 1852 .... appeared Ann Howie from Tannachie, and stated that she had born a child in fornication about four months ago, and that James Gray, lately farmservant at Blairerno, was the father thereof, and who had left this neighbourhood - and she was unable to tell whither he had gone or where he might be found. She was admitted to discipline, and being solemnly rebuked and exhorted to repentance was absolved from the scandal. [National Records of Scotland CH2/1150/3/165]
Tannachie and Blairerno are quite close together.
See
https://maps.nls.uk/geo/explore/#zoom=15&lat=56.94526&lon=-2.35527&layers=5&b=1In the 1851 census there are several households of Howies at Tannachie in Glenbervie
(1) David Howie, 62, blacksmith, born Fordoun; wife Elizabeth,62; daughter Hellen, 29, son Joseph, 15, grandson David Smith, 9. All but Davis Smith born Fordoun.
(2) William Howie, 29, Blacksmith journeyman, born Fordoun; wife Mary, 29 and son David, 3.
(3) John Howie, 23, born Fordoun; wife Margaret, 25 and son Robert, 5
In 1841, at Tannachie, are David Howie, 50; Bettie, 50; Ann, 11; Alexander, 8 and Joseph, 6.
Ann Howie, 21, born Fordoun, is a servant in Drumlithie in 1851
Ann Howie, 30, born Fordoun, is a dairymaid at Balfeigh, Fordoun, in 1861
Ann Howie, 39, born Fordoun, is housekeeper at East Tullo, Garvock, in 1871
Ann Howie, 50, born Fordoun, is housekeeper at Bridgemill, Marykirk, in 1881
Ann Howie, 57, born Fordoun, is housekeeper at Bridgend, Marykirk, in 1891
Ann Howie, 66, mmn Tavendale, died in Montrose in 1899.
The only Howie baptism in the Fordoun parish register with mother T*vendale is William, son of David Howie and Eliza Tevendale in 1821, which is an exact match for the age of William in Tannachie in 1851.
Helen Howie, mmn Tavendale, died in Glenbervie in 1858, aged 39
William Howie, mmn Tevendale, died in Glenbervie in 1883, aged 62
Joseph Howie, mmn Tavendale, died in Glenbervie in 1915 aged 77
So I think the inescapable conclusion is that Ann Howie, mother of James Gray's illegitimate daughter Ann, was the daughter of David Howie and Elizabeth T*vendal*.
David Howie, mmn Nicol, died in Glenbervie in 1874 aged 87
Elizabeth T*vendale or Howie, mmn Watson, died in Glenbervie in 1855 aged 66.