Catherine Kirchoff Rohrs (Haase) - Mother of Mary Rohrs

I've just recently started looking further into the life of my great-great grandmother, Catherine Kirchoff Rohrs Haase and the research has been a challenge. Catherine Kirchoff was married to Wilhelm Rohrs in Germany (somewhere to be determined) and together they had one child, Maria/Mary Rohrs. The couple sent their only child to America at the age of thirteen. Why? I wish I knew.
Minnie Elling remembered that her grandmother came to America after the death of her first husband, Wilhelm. Also she gave me the clue that Catherine had married a Haase once in America and the couple had lived in a log house in Freedom Township, often visiting in their horse and buggy. So...that's what I had to begin the task of learning about Catherine.

I knew she was not in the 1880 census and again, without the 1890 census, the first time I found Catherine is in 1900 where she is the wife of Christian Haase, living on a rented farm in Freedom Township. Christian was able to speak English, while Catherine did not, it was reported. The census confirmed that she had given birth to just one child and that child was living. Christian's age was given as 66 and Mary's age was 57; however, her birth date was reported as 1841. The census said that she has been in America for 7 years and Christian for 15 years, making her immigration date in 1893, which seems unlikely, as she would have been separated from her daughter over 15 years at that point. Christian's immigration date was given as 1886 and hers was left blank, unfortunately.

The 1910 census found the couple still in Freedom Township on a rented farm, with Christian now at 76 years of age and Catherine at 67. She was still not a speaker of English. This census noted that they had been married 15 years and gave Catherine's immigration date as 1887. The 1900 census said they were married for 7 years at that point, so the range for their marriage date is 1893 - 1895.

Christian died in Henry County on July 22, 1914, and Catherine died in Fulton County on December 8, 1916. One could assume that perhaps she went to live with her only daughter Mary and husband after Christian's death.
So I have much to discover about Catherine yet. Her immigration record eludes me. No record seems to fit her profile - did she use an alias? (Just kidding.) I need a trip to the Henry County courthouse to find a marriage record and maybe a naturalization record, if it exists. Maybe I can find some obituaries to help. Wilhelm Rohrs, who never came to America, will be a real challenge. The name Rohrs is much more common than Kirchoff and with not much to go on, finding information on our great-great-grandfather would probably include hiring a German researcher.