Austria had an Empress, not a Queen so what is the title about? She married Sigismund III Vasa, king of Sweden and Poland. It was a love match. The Poles sent border guards to keep her out, but she infiltrated, got to Kraków and married and became Queen. When she followed Sigismund to Sweden to be crowned at Uppsala, the Poles demanded she leave her daughter behind. They had five children, but only Vladislaus survived to adulthood. Sigismund remarried another Habsburg, Anna's sister Constance.
Anna's Wikipedia article is here.