Betty Jean Earnst or Ernst

I am searching for any clues to the original family of two small girls adopted in 1931 from a Fort Wayne orphanage. The application to the court states they were under care of Board of Children's Guardians of Allen County. Their original names are Betty Jean Earnst (b 1927)and her baby sister Evalyn Earnst (b 1929). It could be Ernst or Earnest. The children's names were changed to Gene Ann Zimmerman and baby sister to Geraldine Zimmerman, after the adoption became final in 1931. I welcome any tips or clues! Thanks!