Do you have Charlotte's obituary? If Harriet married it may list her.
It was in Columbus Dispatch.
http://www.columbuslibrary.org/cmlcnix/searchobitform.cfm 1. Obituary
Publication: Columbus Dispatch Date: Saturday, December 18, 1965 Page: 2
If you don't have it you can request a copy from Columbus Library. Click on e-mail a librarian at the link below and provide them the details.
http://www.columbuslibrary.org/They usually e-mail the obit. No library card is required.
Also you can look at some of the Greenlawn records at:
http://greenlawn.delawareohio.us/greenlawn/Greenlawn/index.h...I noticed Harriet Miller is buried there.
Jim