Was Edwina Kanis the one who married Ferdinand? If so, then I think she must be my mysterious "Mina." I think that I was jumping to conclusions to think that Emma Kanis was Mina because the name Emma appears much more frequently in Rosetta's things. The only mention of Edwina is the one in her address book, and I think I had overlooked that until I made yesterday's posting.
Yes, this is exciting. I can't wait to share some of this with my dad.
One other thing - I have photographs of Georg Albrecht Thoma and Margaretha's gravesites in the Allegheny Cemetery in Pittsburgh, PA. I'll send you copies once I get them made.
I'm looking forward to learning more!