Thank you. Yes, this is my 2nd great grandmother, Marthine. We know where John (her biological father) is, but not where her biological mother (Lise) is. According to the obituary, Lise died when she was 5 years old so abt 1875. According to mom, she remembers that Marthine was sent to LaCrosse, WI to live with Skogstads (perhaps for a short time), then moved back to SD where John's sister, Ingeborg, raised her. Mom doesn't think the ones in Lone Rock are the ones that took her, but working from memory. We went through the line with the caretaker for Lone Rock (she actually knew these people) and we did not find anything there. We went through everyone there and Lise and her mother, Kari, are not there.
I don't get the impression that John was marriage material given that he appeared to have 3 children with two different women and left Norway for US. I find no evidence that she went to the same area that he lived. Only after her death when Marthine was sent to him and raised by his sister. The last that I can find any trace of them is Grosse Isle as you indicated, and Police Emigrant Protocol and Passenger List. And I agree that they don't provide a way to see those. I mean that the last record found is Quebec Grosse Isle. I find no sibs with the same mother. And the others didn't come here (USA) to my knowledge.
I never saw that record of the woman that died at sea, but that's what i suspect...something like that. But I can't prove it. I don't think this is ours...but will keep an eye on that one.
Another thought is that they changed their names, but no clue where they are.
Nice maps! Thanks!