Have look at the answer below, which may answer most of your questions.
The important point is:
Did you, as a adult, ask for and recieved a foreign nationality?
when no: apply for Staatsangehörigkeitsausweis
This assumes you were German through birth (before foreign birth registration)
one of your parents were German
germany - Does ...
Since 28. August 2007, where in Section 25 (1) sentence 2 StAG was added.
§ 25 Abs. 1 Satz 2 StAG
Der Verlust nach Satz 1 tritt nicht ein, wenn ein Deutscher die Staatsangehörigkeit eines anderen Mitgliedstaates der Europäischen Union, der Schweiz oder eines Staates erwirbt, mit dem die Bundesrepublik Deutschland einen völkerrechtlichen Vertrag nach § ...
The current state of the relevant law may be found at 8 USC 1321(a). This contains another condition that you do not mention, which is that the child must have a green card:
(a) In general A child born outside of the United States automatically becomes a citizen of the United States when all of the following conditions have been fulfilled:
(1) At ...
When living outside Germany an application should be made at the local consulate that is responsible for your area. It can be made directly to the Bundesverwaltungsamt, but not to the local reponsible authority (Staatsangehörigkeitsbehörde) in Germany (which in Berlin would be the city district of permanent residence).
No, the time needed for the ...
Yes, from the conditions stated it would seem you fulfill the:
French citizenship acquired automatically at age 18
condition listed below.
You should check if your mother still has her French passport.
If she was became a Canadian citizen, Nationalization papers was well.
these documents and birth certificates may be helpful
I haved added a link ...