Looking for records on Polish great grandmother Johanna Pospeieszna listed in Baltimore MD census in 1940 but not 1950.Living with my grandparents Louis & Martha Konieczny in 1940.

Looking for any records relating to my Polish born great grandmother Johanna Pospeieszna listed in Baltimore MD census in 1940 but not 1950. She was living with my grandparents Louis & Martha Konieczny in 1940 census at 619 S. Milton Ave. in Baltimore MD.  She is listed as widowed, 75 years of age, so Pospeieszna may be her maiden name and I believe her married name was Johanna Boracki.

Any help is appreciated.  I need to verify that she and my great grandfather on my grandmother's side were born in Poland.