Anne, the name "Valentine" is unusual.For this reason I want to point out a family to you.
Alexander Walker, Jr was minister in Surry Co (from James City Southwark Parish 1701-14 (VA Mag Vol 1 p 369).We know that Alexander m Jane Freeman b ca 1675. Known children were James; Henry m Lockey ?; David m Mary Mumford.Henry had children Benjamin, Alexander, William, David, Jane, Henry & Freeman.The latter Freeman died in 1790 as did William, Alexander. Freeman was m to Sarah Minge who moved to GA with her 5 children:Wyatt, George, Robert, Valentine and Freeman, Jr.
Don't know if these names were in descendants of Benjamin F or James V., and am passing it on as one more possibility.However, I think that with your Benjamin being b in MD, he would not be of this family. W. Ray Walker