Helen Hyslop, also Nelly or Ellen Hyslop was a noted local beauty in Moffat and a strong local tradition maintains that Burns was for some time a great admirer of her and she had an affair with Robert Burns . A daughter Helen is said to have been born as a result of the liaison. Parish records show that a Helen Hyslop was born in the area in 1766, her parents being John Hyslop and Janet Howatson of Langholm.
An article was published in a Moffat newspaper in circa 1885 recalling that a Mrs Richardson of Moffat, born in 1864, recalled running messages as a child for Helen Armstrong and knew her as a daughter of Robert Burns.
Source: Wikipedia