It is interesting that your family was Prussian but had a connection to Holland. My aunt (nee Leona Clark)said that the family always thought her g-grandmother Catherina Epker was "Dutch" and didn't learn that she actually came from Hanover (still don't know if that was the country or the city)until they saw her obituary. Frederick Epker and his brother were born in Germany in the 1830's. At that time people took the name of the landlord. My mother (Frances Clark) said they didn't like their last landlord, Herr Schlinkner (however it is spelled) so they reverted to the name of the previous landlord whom they did like --Herr Epker! No hard evidence for that, just stories
from my mom. PS: Note Catharina Epker> Louisa Elizabeth Epker> Henrietta Louisa Reed> Frances Louisa Clark