Interestingly, Marilyn Monroe only found out about her half-sister’s existence at the age of 19.
On July 30, 1919, Berniece Baker, half-sister of actress Marilyn Monroe, was born. They had the same mother, whose name was Gladys Pearl Baker (née Monroe). That mother got the aforementioned daughter Berniece Baker in her first marriage, and only later Marilyn Monroe (Marilyn Monroe’s birth name was actually Norma Jeane Mortenson, or Norma Jeane Baker).
Interestingly, Marilyn Monroe only found out about her half-sister’s existence at the age of 19. They first met in 1944. Berniece Baker was almost seven years older than Marilyn Monroe, and had one daughter – Mona Rae – with whom she published a book called My Sister Marilyn after Marilyn Monroe’s death.