Brief review of info:
Samuel Friedrich Schulenborg was born August 5, 1860
Marriage Records, St. John's Luth. Church 150th Anniversary Book, Farmers' Retreat, IN. 1993, p.75 state
Samuel Schulenborg m. Elizabeth Knollman Oct. 15, 1885
Rev. C. Kretzman (officiated)
There is no mention of a marriage between a William Schulenburg and an Emily at that time in the book.
My records for Samuel's brother: William Heinrich Schulenborg, however show:
1876 - Jan 13 - William is married to Eliza M. Brocksieker (nee Rolf) - (Elizabeth's husband died of smallpox in 1871; he was one of four that died and are buried at the Ellerman cemetery. The first husband of Dorothy Tepker (nee Rolf)and their child also died in that group.)
1879 - William moved from Tipton Co. to Ripley Co. when son, Robert, was three (according to the later obituary of Robert)
1880 - William (age 29/1851) and Eliza H?M [nee Rolf/ Brocksiecker] (age 27/1853) Schulenberg now live somewhat near Fred Strieck and his second wife, Catherine (Dorothy Rolf/Tepker/Strieck already died). Living with them is son, Robert G. (age 3/1877), sister, Mary C. (age 25/1855), brother, Paul ?S. (age 17/1863), brother, Samuel F. [blacksmith] (age 19/1861), brother, Robert H. (age 15/1865), and niece, Helen Tepker (age 11/1869)[Helen Tepker was the daughter of Dorothy Strieck (nee Rolf/Tepker)and now that her mother was dead the Schulenbergs who blood relatives, would have been the logical place to live since Fred Strieck was a step parent with a new wife.]
[1880 Census: IN, Ripley, Brown Twp., ED 152, p. 12. Can be found on Ancestry by looking up Helen Tepker]
1900 - I can't find William; but he is listed in the Farmer's Retreat book as dying in 1904, (p. 59) so I should find him somewhere in the 1900 census.
I know this gets a little convoluted at times, but it all pans out.
Where did you get the info about a marriage between William and "Emily"?