I also have a great-great-grandmother named Bertha (Erdmann)Henke. She married Frederick Michael Henke in Germany and came to the U.S. about 1887-88. Her Mother's name was Wilhelmine. Bertha's son Otto William August Henke had a daughter named Wilhelmine. Otto W. is my paternal grandfather, his son Otto Michael was my father. If these are names you recognize please let me know.