Bauch family Germans from Russia

Searching for info. on the family of Marie
Sandau nee Bauch. Marie died 1904 Kronental(Deutsch-Chaginsk) NordKaukasus russia,Lat 46 17'N Long.42 16'E. Her family possibly immigrated from Bessarabia 1860's.
Her descendants ,Sandau's immigrated to USA 1906-1907. Prior to the families time in Bessarabia they may have lived in Poland.