Hi Charlene, and thanks for your help.I think you're right about the Shuler family in Aurora in the 1870 census being mine.That gives me a birth month of Jan 1869 for Nick Shuler.
No, I've never seen Eva Mirkes Schuller being called Margaret anyplace else.Her birth record in Germany, as well as all the later US censuses (1880, 1900, 1910) call her Eva.She is also called Eva in the Aurora City Directory of 1910-1911.
Worse still, her younger sister was named Margaret (my great-grandmother, Margaret Mirkes Wagner 1854-1914).It seems unlikely that Eva would borrow her younger sister's first name.We can probably chalk this one up to census-taker error.
To finish off Eva, she was baptised in Jucken, Rhineland, Prussia on 13 Jan 1845, the daughter of Jakob Mirkes and Catharina Bretz.Jucken is near the border with Luxembourg, so that may be why there was some confusion on the part of the census-taker, who listed Eva's birthplace as Luxembourg, not Prussia.
John and Eva are not listed in the 1920 census and their children Frank and Elizabeth are living in their home.So John and Eva probably died between 1910 and 1920, but I cannot find them in the Illinois Statewide Death Index under any reasonable spelling for the surname Schuler/Schuller/Shuler, etc.