Here is Gene Tierney and Marilyn Monroe wearing the same dresses, with Marilyn in publicity stills in 1952 and at The Henrietta Awards in 1952 and Gene in Where The Sidewalk Ends in 1951 and On The Riviera in 1951.
This also shows how frequently clothes were reused by other stars and how it was not a big deal to do this during the 1940s and 1950s.
The dresses were designed by Gene’s then husband, Oleg Cassini, who also designed Veronica Lake’s costumes in her breakthrough film, I Wanted Wings (1941)
Although, as far I’m aware the two never met, they both lived across from each other in the late 1950s when Marilyn was married to Arthur Miller. Both suffered with depression and anxiety, both were signed to Twentieth Century Fox, both at different points in their lives miscarried and were put into Mental Institutions.