Trudy, Based on your posting, it sounds like you viewed the actual baptism record from Luisenstadt church in Berlin.If so, you may've been able to identify a street address where the family lived, e.g., Alexandrinenstr. 9, or something like that.If yes, then some times the Population register films available for the inhabitants of BERLIN may be helpful.That's how I found the ancestors for my WEGENER in BERLIN, similar time period as yours.Note that only major streets are filmed.
For familysearch.org FHL film details, go to: Germany, Preußen, Brandenburg, Berlin - Population, Einwohnermeldebücher, 1813-1824
There are 15 films for several major streets.
Notes:Population registers of inhabitants of Berlin, Brandenburg, Germany. Includes Stralau. Includes vital data on residents showing names, religion, age, place of birth, of the father, mother and children. Includes lodgers, servants, step- children, and foster children. Text in German.