Since you know Elizabeth's death date, have you ordered her death certificate?It should list the names of her parents, to the best knowledge of the informant.
The 1900 census shows that Elizabeth immigrated about 1860: 1900 United States Federal Census > Louisiana > Orleans > New Orleans Ward 7 > District 74 > Page 7A Frenchmen Street(rents home) Dwelling 117/Family 119 Elizabeth Daussat, head, white, female, born April 1833.AGe 67, widowed.She and parents b Germany.Immigrated to the US in 1860.reads, writes, speaks English
You might want to check immigration records in New Orleans to see if you can find her.They should tell where she came from, at the very least.
Good luck! Karen
She is also listed in the 1880 census in Orleans Parish.If you don't have this census already, you can get it for free at www.ancestry.com