POTOSI - The world lost a beloved mother, Cornelia Catharina Fishnick, on December 18, 2021. Cornelia was born in Amsterdam, Netherlands on July 28, 1929 to Leonardus and Cornelia Koster. Funeral services will be held Wednesday, December 22, 2021 at 10:30 a.m. at Martin Schwartz Funeral Home & Crematory in Lancaster, with Reverend Pamela Strakeljahn officiating. Burial will be in the Van Buren Cemetery, Potosi, Wisconsin. Family and friends may call on Wednesday, from 9:00 a.m. until time of services at the funeral home. Martin Schwartz Funeral Home & Crematory in Lancaster is assisting the family.