Yes.
First of all, that's *Hedley*.
Second, Joan Bennett and Hedy Lamarr are not sisters. Hedy Lamarr's
original name was Hedwig Eva Maria Kiesler, and she was born in
Vienna. Joan was born in Palisades, New Jersey, to a theatrical family
and had two sisters, Constance (also an actress) and Barbara (who
married Morton Downey Sr. and became the mother of Morton Downey Jr.
-- yes, *that* Morton Downey Jr.).
No other details are available. This is because they are, in fact,
not sisters. Unless Joshua Collins doctored their records too.
They both did lots of work in the 1940's, but I believe they never
appeared together, as they most likely belonged to different studios.