It seems the granddaughter was still looking as of 2003 and may have found a possibly other last name for Bertha - HAEFT.
Does anyone know the names of the sons of Bertha? I do not have ancestry access right now, so am having a hard time. There is an obit for Bertha Haeft here:
Toledo Blade - Google News Archive Search
that lists some sons names, but those could also be the names of her husband's children.
ETA: - I believe I found this Clarence and Bertha in the 1940 census, and therefor can't be her since she was missing in 1948! :/