I need to get serious about what kind of actual records I have of Sarah placing her at different times. For instance, I don't think I have their family in the 1880 Census...yet. So I searched for Van de Riet in Kansas, 1880 on familysearch and came up with lots of relatives in Smith County, but so far no Herman. Where were they in 1880? It looks like #2, Aunt Grace was born Dec. 1880, so I checked her as Grace Bos, Minnesota. On the 1930 Census Index, familysearch she says she was born in Kansas. (I also see that she left a possible will in the Minnesota Will Index, check into this later.)
Okay, so how about Uncle Will? Yes, in 1910 he also claims a Kansas birthplace, circa 1877.
Next I guess I want to scroll through the Van de Riet neighborhood myself in 1880 and see if I can come up with Herman and Sarah.
Interesting, the old familysearch site does not have the same ones as the new on the Kansas Census, and I can't seem to find the right ones. A slipper bunch! Maybe some land records would be better. Time for US Genweb?
Also, looking at the dates, it seems that Sarah would have been a teenager when married. About 17, almost 18 if I have the right dates. Did they elope?
US Genweb is pretty sketchy for Osborne County and Smith County. Also searched on the Kansas archive link on US Genweb and only got one hit for Van de Riet. Here is the land patent for John Van De Riet 1872, in Smith County. No other Van de Riets came up on the BLM website for Kansas.
Google search for Herman Van de Riet--Mostly Dutch, not helpful.