I received information about the two books on Silhouettes that I was looking for. They contain references to the Ball Hughes family silhouettes by Auguste Edouart in 1842. I had hoped that the books would contain images of the silhouettes but they didn't.
I did learn the Arthur S. Vernay purchased the silhouettes from Emily Jackson. She acquired them after they were recovered from the shipwreck of the Oneida on Edouart's return to France in 1849.
Vernay exhibited the silhouettes, including at least one of Ball Hughes, at the Art Institute of Chicago in 1914 before selling them. Read more about it on the Silhouettes by Edouart page on RobertBallHughes.com.