I've decided during this Corona period to gradually outsource to the JewishGen readers the major brick walls in my family tree research. Here is the first one.
Elias Heimann DAHL and Sibilla MEYER had 12 children; 9 of them have available records showing their births, marriages, families and deaths.
However 3 of the sisters only have birth records: Rosette DAHL, born 30 Apr 1842; Rosalia DAHL, born 5 Feb 1850; and Mathilde DAHL, born 7 Sep 1854. They were all born in Geilenkirchen, Germany. The Geilenkirchen archive has no further records relating to these sisters and they don't have graves in the Geilenkirchen Jewish cemetery. (Geilenkirchen is North of Aachen, close to the Dutch border.)
There are no additional details and several years of online and direct enquiries have not uncovered additional information.
Any assistance would be appreciated.