Well I'm not saying this is great proof, but it dose say mother of lot owner Frank J.
I took a look on
www.familysearch.org for marriages on Bernhardt's. Found a few, and it also listed the 1880 Census with Barbara. There is Eva Hoffman, born 1808. Some other members too.
https://familysearch.org/pal:/MM9.1.1/MHSN-5DHNot finding her in the cemetery listings.