Mary De Loach (aka Mary DeLoatch, Marylin Scott or Marylyn Scott the Carolina Blues Girl) was from Norfolk, VA and started a career as a blues guitarist and vocalist in the late 1940's. By the early 50's her music had taken a gospel turn, and her raw guitar style, of course, draws parallels with Sister Rosetta Tharpe.
Apparently, this was the last record she ever cut, and the rest of her story after this point is unknown. Producer Louise Williams (wife of Arctic Records founder Jimmy Bishop) was known as the gospel radio queen of Philadelphia (note that the record's publisher namechecks this), and since the late '80's she's made a name for herself as a politician in Philadelphia. Perhaps Louise Williams was a fan who brought Mary north to Philadelphia to record? I read somewhere that this record deals with marital problems that Mary and her husband were having, and given the context of the lyrics that story makes sense.
Whatever the story, it's truly a wonder that a performance like this was captured by microphones; it's as if we're witnessing something almost TOO personal here. It was cut to wax in 1967, and I took the liberty of editing parts one and two into one piece (luckily, the fade out/ fade in's made the editing rather seamless).