I am currently researching my husband's family. His great grandfather is John Noble Alexander who married Armenia (Minnie) Roy and lived in Goodland, Indiana, whichis in Newton County.Newton county is right next to Benton County. This area is still very rural and sparsely populated.John N. Alexander had a sister named Della who is probably your Delphine. Minnie had a brother named Adolph Roy. I think that a brother and sister in the Alexander family married a sister and a brother in the Roy family.
According to my husband's grandmother, Lucille Alexander Ott, the parents of Armenia Roy are Peter Roy (who immigrated from French Canada)and Sophia Rivard or Revard. Sophia died in 1915 in the Northern Indiana Hospital for the Insane. The parents of John Noble Alexander are Renalda Charis (Charais) and William Alexander.