Agnes's father, Gilbert (1708–1774), was the tenant of the 300-acre (120 ha) farm of Craigenton, in Kirkoswald parish,[4] South Ayrshire, Scotland.

A bed and breakfast called the Whitestone Cottage, on the Culzean estate in Ayrshire, claims to be Agnes Broun's birthplace, however she was christened at Kirkoswald that is close to Craigenton Farm.

As the oldest of six siblings Agnes spent the next two years looking after the family, but in 1744, after her father had found a new wife, she was sent to live in Maybole with Jean Rainie, her maternal grandmother.

Agnes reportedly had no great liking for her stepmothers, the latter of whom was several years her junior and this may explain why Robert Burns had little or no contact with his maternal grandfather.

[10] Later homes were at Lochlea, Mossgiel, Dinning and finally at Grant's Braes, Bolton, near Haddington in East Lothian where she died in 1820 aged 87.

[12] According to Robert Burns's youngest sister, Isabella Begg, she “... was rather under the average height; inclined to plumpness, but neat, shapely, and full of energy; having a beautiful pink-and-white complexion, a fine square forehead, pale red hair but dark eyebrows and dark eyes often ablaze with a temper difficult of control.

Her disposition was naturally cheerful; her manner, easy and collected; her address, simple and unpresuming; and her judgement uncommonly sound and good.

She possessed a fine musical ear, and sang well.”[6] The artist, John Miers, made a silhouette of Agnes, when he was based in Leeds .

Agnes's half-sister was Jean Brown (1750–1821) who, in 1775, married James Allan and lived at Old Rome Ford near Gatehead, in East Ayrshire.

[17] The biographer Hecht relates that "her sweet singing was heard as she went about the heavy work of the day, for she had a good voice and a wonderful stock of old and new ballads and songs, such as were current amongst the people.

To the mortal and immortal memory and in noble tribute to her, who not only gave a son to Scotland but to the whole world and whose own doctrines he preached to humanity that we might learn."