Hi John, In my data I show that the parents of Sarah Hollyday that married Thomas Johns, are Leonard Hollyday and Miss Bradley.Leonard, d ca Dec 1793, Prince George's Co.; he is the s/o Col. Leonared Hollyday, d bef. June 26, 1741, Prince George's Co., and Sarah Smith.
For the name of Leonard Hollyday's wife, BRADLEY, I have not researched it, but I think this BRADLEY name is pulled from the ca Dec 1793 will of Leonard in which he names a dau Ann Bradley Hollyday.
As for the Grace Contee connection, I cannot help there. Good luck, Shirley