I just saw this posting, since I'm sort of reading backward through the thread.
Here's my take: There really was "One" Mielke family in Rib Lake, but it grew rapidly through the brothers and their sons.
"Grandma Kalk" Johanna Kalk m. Friedrich Mielke (she's buried in Lakeview Cem. Rib Lake; he's unknown)
John m. Caroline Hoeffmann
Fred ("Fritz") m. Emma Haemel
Reinhold m. Pauline Helen Klein
Bertha (abt 1903) probably the Bertha in question!
August m. August Rojohan
August m. Bertha Tetzlaff (farmed in Rib Lake)
Martha m. Albert Marschke (died 1907 giving birth)
Augusta m. Fred Whittie (lived in Duluth, MN)
Alvina m. Fred Krueger (lived in Chisholm, MN)
Kathleen (Katie) 1953-
It would be utterly fabulous to learn what you have "in depth family tree back to Germany". Does it verify or prove false the information I have?
If we are truly related, would you be willing to firstname.lastname@example.org
Eden Prairie, MN