Isabel married her cousin Infante Duarte a son of Manuel I and Maria of Aragon in 1537.

Isabel was dowried with the Dukedom of Guimarães, which had belonged to her brother Teodósio I, Duke of Braganza.

After the marriage, Infante Duarte became the 4th Duke of Guimarães.

Her younger daughter Catherine became the Duchess of Braganza and had a claim to the throne of Portugal.

This biography of a member of the Portuguese royal family is a stub.