LloydG on Family Tree Circles

Anna was born abt 1843 in Peitz. Somehow she found her way to New Zealand where she married Hinrich (Henry) Claus Cordes in 1867. They were my Gr grandparents. I am having problems finding more about her and her family in Peitz, and just how and when she arrived in NZ is a mystery. She had very little knowledge of the English language so spellings (Kossarts, Kossety), birthdates etc, are unreliable. Two other Kossatz girls - Christiana and Maria - were here about the same time, but I am unsure of their relationship with Anna, perhaps cousins or even sisters.
Any suggestions welcomed!