Upon his death in 1490, Beatrice managed to keep a power position by the support of the Hungarian nobility and continue as queen of Hungary by marriage to the next monarch.

She presided as a royal representative at the parliament where the next king was elected, with the Hungarian crown placed at her side.

Vladislaus II of Bohemia and Hungary wrote in the same year 1490 many letters with the same text to many of the Hungarian nobility.

Her husband claimed that he did not regard the marriage as legal, and that he had been forced to marry her against his will, and in 1493, a commission was issued to investigate.

In 1500, the pope declared the marriage to be illegal, and Beatrice was forced to pay the costs of the trial.