The Layton Barb Mare was presumably a daughter of a stallion known as the Layton Barb, but nothing is known of such stallion. Layton was an ancient manor near Sedgefield, County Durham, which at the time of the Layton Barb's presumed tenure and his daughter's birth was owned by John Conyers (died 1690).
This mare is listed in the GSB as "Layton (Violet) Barb Mare" with no parentage given.
She is credited with 5 foals, but the last (Young Violet Layton) is foaled much too late and is more likely a granddaughter.
In addition to being the founding mare of Family 4 through her daughter by Dodsworth, she is also dam of the stallions [Darcy's] Counsellor and Burford Ball.