Graef Historical Group

I've been working on the Graef family history and have traced a new line back to a great-great-grandmother, Josephine Mezik (also spelled Meszik). She was born in Bohemia, married Albert Skrabal in Iowa City on 3 May 1865, and died in Nebraska in 1928. Her daughter Emma Skrabal married Jacob Graef. Family identification, not confirmed. The other two women are not identified; they may be her sisters. This is a copy of an old portrait of three young women, labeled “Josephine Meszik (1849-1928 b. in Bohemia) the one in the middle.” I'd love to include it in the family history, but first I want to be as sure as I can that the identification is right. Could anyone help with a few questions? Do you know who wrote that label, and what they based it on? Is there any writing, a name, or a photographer's stamp on the back of the original? Do you know who the other two women are? They may be her sisters. Do you remember how the photo came down in the family, and who had it be...