Thanks for this information! It is very exciting to see the veil of history on Lee Slaughter pushed back a bit more. With this much interest, just as you said, I can't help but think that we can finally solve the mystery of Lee's parents.
I see that a quick Google search on Priscilla Harrington turns up this site: http://edlers.org/notes/p245.htm
Is that who you contacted? It would be very interesting to find the source material for her birth date and the list of children.