I saw her name given as Idabell in some online family trees, and asked my mother if that was really her grandmother's name. She was very insistent that it was just Ida, she was never known as Idabell.
I did a search on FamilySearch just now, and she is Ida or Ida M. in the 1880 census, marriage record with Charles S. Slack, death record for her son Solomon Slack, mother of the bride for daughter Gladys Slack. Are there any documented sources for the name Idabell?