Ancestry.com refers to Anna Fecht as the step-daughter of my second great-grandaunt.
That seems slightly incorrect to me as she was born after my second great-grandaunt, Antje (Habben) Fecht died. Antje was the first wife of a man named Harm Fecht. Harm married after Antje died and Anna was born to that marriage.
I generally do not think of a person acquiring step-children after that person has died.