My Fredreckia Kuehl Jansen was married to Heinrich "Henry" Jansen in Schleswig-Holstein, Germany. They had several children (?) and 3 sons came to Iowa; Frederick, Nicholas, and Louis. Louis is my GGrandfather. Maybe your Fredrickia was a sister or a daughter to Heinrich?
There a few "Mohr's" in Lost Nation, IA, and in Manning, IA. Heinrich and second wife-Katerina Plombeck/Langbehn immigrated from S-H Germany to Lost Nation, IA, then on to Manning, IA. Do you know where John P Mohr is from? Maybe there is a connection...?
The "dutch girl" maybe from "deutschland"(german-land)..."Sprechen Sie Deutsch?" ("Do you speak German"?)
Let me know if I can help further...we may find a "connection"!firstname.lastname@example.org