Fritz BEYER and Emma KOSTEN/KASTEN - late 1800s - Illinois

I am searching for any details on the parents of my great-grandmother Christina Anna KOSTEN (1897-1986).I have seen the variant spelling of "KASTEN," and after looking through several online databases and seeing the plethora of KASTEN'S, I think this could have been the "original" spelling.

According to the church records of St. John's Evangelical United Church of Christ, in Collinsville, from 1895-1913, Christina's parents were Fritz BEYER and Emma KOSTEN.Fritz's name was in parentheses, and written in the margin of the baptism record was "emergency baptism."I'm not sure if they were actually married, as their surnames are different in the record.Also in the record were the names of the baptism sponsors: Ottja KOSTEN and Anna SCHALLER, nee SCHOENWINTER, as well as the note that "the grandfather's full name was KOSTENHOSEN."Christina married Louis GEMOULES, an immigrant from Greece, and they lived in Edwardsville.Any insights into the names Kosten/Kasten and Beyer would be much appreciated.Thanks!