My paternal grandmother was Antonette Johanna Post, born in Amsterdam in 1879. She married Wilhelmus Johannes Roosen and one of their sons was my father.
To date, I have only researched this family through internet sources but I have discovered that she is part of a substantial Post family tree.
Antonette's ancestors originated in Weesp, North Holland and I have some information dating back to the mid-1700s but there is much more to be discovered