She was the daughter of Ferdinand I, Holy Roman Emperor and Anna of Bohemia and Hungary.

Eleanor was the eighth child and sixth daughter out of fifteen children born to King Ferdinand of Bohemia and Hungary (before his succession as Holy Roman Emperor) and his wife Anna of Bohemia and Hungary.

At about age five, Eleanor's daughter Anne Caterina became severely ill and nearly died.

Eleanor and William told their daughter of the Virgin Mary's intervention on her behalf and the promise they had made.

From there out Eleanor educated and guided Anne Catherine in the cultivation of devotion to Mary.