I know it's a long shot that you will even get this, since you posted your message almost 9 years ago(!), but I thought I'd try anyway.
I am looking for my ancestors on my maternal grandmother's side, and am hoping the Dupuy family you write about might be hers. I know almost nothing about her except that her name was Marie (perhaps Mayotte, although it's possible Mayotte was just a nickname) Dupuy, and that she married Fritz Thiesfeld and they had three children, Gertha, Franziska, and Johanna. Johanna was my mother. I am told Marie died in 1923 (the year my mother was born). That is all I know.
If you have found the name Thiesfeld in your research enywhere, this might be the link to her side of the family tree.
Thanks in advance for any information you might have.