Katalin was the daughter of Péter Középlaki and Erzsébet Iklódy. The date and place of her birth have not been found.
She had two marriages/partners. Her first husband was István Kemény. They were married, but the date and place have not been found. Their six known children were Mihály (?-<1471), István (?-?), Péter (?-?), Márta (?-?), Anna (?-?) and Margit (?-?).
Her second husband was János Mikola de Dezmér. They were married, but the date and place have not been found. They had no known children.