It would appear that your Jacob had a younger brother George and that they lived near by each other in the township of Franklin in Kewaunee county WI. George and Barbara had a son Frank Kozina who became a doctor and practiced in Milwaukee. He married Arlene Emily Skochpol - the daughter of Joseph Skochpol and Mary Zima. You will notice that the Zima family lived closed by the various Kozina families in Franklin township per the 1900 - 1920 censuses. Dr. Frank J. Kozina died 7 Feb 1961 at age 51 and is now buried next to his wife who died 25 May 1994 at Mount Olivet Cemetery And Mausoleum. By my calculations, Frank would have been your Jacob J. Kozina's nephew.
Hope this may be of some value to you,