You might try to contact the Barry County Public Library.
Talk to someone in the reference or genealogy department.
Ask them if the have a death/obit database for the local area.
Ask about back issues of the local newspapers to locate obits for your couple.
The obits should give the names of the surviving family members.

You might try contacting the Barry County Genealogy Society.
They may have a local volunteer who would be willing do help with this research.

You might try putting an add in the Barry local newspaper.
Tell people who you are looking for and that you have family items to give them.

good luck

Susan
Saginaw, Michigan