[1] Poser was born as Lydia Orban into a working-class family in Heidersbach, now a part of Suhl.
After completing her studies at Volksschule and Lyceum, she trained for work as a typist and took a job with a Jena engineering business.
From November to December 1933 she was in the district court jail in Weimar, and was then transferred to the Bad Sulza concentration camp.
In April 1934, she was convicted by the Superior Regional Court (Oberlandesgericht) in Jena of "preparation for high treason" and transferred to the women's prison in Gräfentonna.
From 1950 to 1963, she was a member of the national legislature ("Volkskammer"), sitting as a representative of the ruling Socialist Unity (SED) party.