Hello Mary, Mary Ohmer is my great-great-grandmother on my maternal side. In the family history book we have, Carolina Fredericka was married not to Harold Ohmer, but Carl "charles" Ohmer. Fredericka was born November 26, 1841 Married April 7, 1864 to Carl Ohmer Died May 30,1929 in Mayville Michigan Her parents were Frederick ellwanger and Catherine Hawn. Her brothers and sisters were Christina, Catherine, Wilhemina, Frederick, Mary & Carl (twins), William, and Paulina. She came to America June 18th, 1861 from Haberschlach, Wurttemberg Germany Her children were: Caroline, Ella, Belle (Pauline), William, Thersa (Jessie), Katherine (died at 19 in 1887), Anna, Margaret, Charles, Grover (cleveland), and of course Mary Wilhemina.
I am unable to find more information on her parents, but maybe you will have more luck! I hope this has helped! My mom also has a few photos of the family and has posted them to ancestry, but if you email her, I'm sure she would love to send them over email.