Not sure if it would be a match, but my g-g-grandfather was Heinrich Janke, last lived in Bandekow. Married to Wilhelmine Krueger (born 1833); had 6 children but their last son J.F. August was born in Bandekow. Heinrich Janke/Jahnke died in Germany. Wilhelmine imm. to MN and then to WI. in 1883. I don't have year of birth for Heinrich but would be around the time of your Frederika. Possible siblings??