Erika Siilivask was born Erika Leontine Vassar in Jõksi, Governorate of Livonia, Russian Empire, the daughter of Gustav Vassar (or Wassar, 1869–?)
In 1928, she graduated from the Pallas Art School in Tartu as a drawing teacher.
[1] Starting in 1928, Siilivask worked as a substitute teacher in the schools of Võru County.
In 1941, she became the head of the education department of the Võru County Executive Committee.
[2] From March to July 1943, she was the head of the Magnitogorsk orphanage, and from the fall of 1943 the director of the Uvelka Children's Home in the Chelyabinsk Oblast.