Pepper/burmeister

Hello, I am seeking information about Margaret Pepper, who was married to Christian Burmeister, blacksmith, Hanover c, 1800's. A son Charles, born Hanover, c 1838, went to London, married Mary Ann Oppenheim, 1860, then they emigrated to New Zealand, 1865. Have had no success tracing Margaret and Christian in Germany. On Charles's death certificate, place of birth is Hanover, but perhaps it was in a small town belonging to Hanover. Would like to know if Charles had siblings.
Hoping someone else is researching Peppers near Hanover,
                                                                                     Betty Burmister. NZ