My grandmother is a German Rieck - Bertha - my dutch grandfather - her husband - picked her up somewhere along the Rhine-river in his times as a shipper on this river and took her with him to Holland (quite romantic, hm?)
I do not know where she was born exactly - it is somewhere in the Mannheim/Heidelberg area in the south of Germany.
As far as I know, my grandmmother Bertha Rieck had the following brothers and sisters: 0Albert Rieck - i know nothing about him 0Herman Rieck, who emigrated to the US 0Amalia Rieck, who stayed unmarried 0Anna Rieck, who stayed unmarried, emigrated to the US (Chigaco, afaik, and had quite some things to do with the Loeb-family there)
And besides that, she - Bertha Rieck - had quite a lot a steph-brothers and sisters - but I'm just starting to work that part out ..-)
As far as I know, her mother was called Amelia/Amalia Gruszkinsky and mm, that sounds rather Polish to me.