Jon,
BG actually gave the name of the alleged singer Ginger Jack Woodrich who lived near BG and from whom he had indeed collected a substantial batch of songs. However it is easy to demonstrate that 295B is a concoction of 2 late 18th century broadsides, the first 295A (also sent to Child by BG) which is quite scarce, sometimes called The Cruel Nymph, the version he found being The Brown Girl; and a very common broadside which continued to be printed under various titles in the 19thc and entered oral tradition, often called 'Sally and her True Love, Billy'. Indeed American collectors upto the 1950s were still giving these common versions as secondary Child ballads. Thankfully that practice has now ceased.