Janna, Pieter and Siert are all buried in Prairie View Cemetery in Grangeville.
The following info is from the Cemetery book:
Janna VanZanten Medema B. 20 Oct 1878 D. 21 Aug 1959 dbl stone w/Siert reads "Revelations 14:13"
Pieter Medema B. 25, Sep 1893 D. 27 Apr 1983
Siert Medema B. 22 Oct 1877 D. 23 Mar 1943
I will be going to the library next week and will search for obits for you. In searching my index I find that there are funeral home records as well. I will take a look at them too.