There isn’t very much information, but here is what there was.
Cemeteries of Brown County, Illinois, 1825-1972
Hersman Cemetery, Mt. Sterling Township, p. 140
Edward Baldwin 1881-1958
Lulu Heitz Baldwin, 1895-1951, wife of Roy Baldwin (no dates – he is apparently not buried here)
Grover Baldwin 1885-1967, a brother to Roy Baldwin
Amelia (no maiden name given) 1888-1962, wife of Grover Baldwin
He may have been a brother to Roy & Grover Baldwin, also mentioned in this cemetery, where at least Grover is buried. In case they might be of interest to you at some point, I have listed them, as well.
You may be able to get their marriages from the Illinois Marriage Index, which has a link on our sight.
Hope this helps.
Could you please look up in the Cemeteries of Brown county, Illinois, 1825-1972 book for Edward Baldwin, p 140, to obtain his death date and burial place?
I am also interested in any info on his wife Nellie Dunbar Baldwin.
Thanks for volunteering your time and efforts to assist others!
C. A. Rose