Wikipedia has this about her:
"Archduchess Maria Theresa (Isabella) of Austria (31 July 1816, Vienna – 8 August 1867, Albano) was the second Queen consort of Ferdinand II of the Two Sicilies.
Family:She was the eldest daughter of Archduke Charles, Duke of Teschen and Henrietta of Nassau-Weilburg.
Her paternal grandparents were Leopold II, Holy Roman Emperor and Maria Louisa of Spain. Her maternal grandparents were Frederick William of Nassau-Weilburg (1768- 1816) and his wife Louise Isabelle of Kirchberg.
Frederick William was the eldest surviving son of Karl Christian of Nassau-Weilburg and Princess Wilhelmine Carolina of Orange-Nassau.
Wilhelmine Carolina was a daughter of William IV, Prince of Orange and Anne, Princess Royal and Princess of Orange. Anne was in turn the eldest daughter of George II of Great Britain and Caroline of Ansbach.
Marriage:On 27 January 1837, Maria Theresa married Ferdinand II of the Two Sicilies. The bride was almost twenty-one years old and the groom twenty-seven. They had twelve children together:
* Lodovico, Count of Trani (1838 – 1886). Married Mathilde Ludovika, Duchess in Bavaria, sister of Empress Elisabeth of Austria. Their only daughter, Princess Maria Teresa of Bourbon-Two Sicilies, married Prince Wilhelm of Hohenzollern-Sigmaringen.
* Alberto, Count of Castrogiovanni (1839 – 1844).
* Alfonso, Count of Caserta (1841 – 1934). Married his first cousin Princess Antonietta of the Two Sicilies and has issue. The current lines of Bourbon-Sicily descend from him.
* Maria Annuziata of Bourbon-Two Sicilies (1843 – 1871). Married Archduke Karl Ludwig of Austria.
* Maria Immacolata Clementina of Bourbon-Two Sicilies (1844 – 1899). Married Archduke Karl Salvator of Tuscany.
* Prince Gaetano of Bourbon-Two Sicilies (1846 – 1871). In 1868, he married Isabel, Infanta of Spain (eldest daughter of Queen Isabella II of Spain) and was created Infante of Spain.
* Giuseppe, Count of Lucera (1848 – 1851).
* Maria Pia of Bourbon-Two Sicilies (1849 – 1882). Married Roberto I Duke of Parma and Piacenza.
* Vincenzo, Count of Melazzo (1851 – 1854)
* Pasquale, Count of Bari (1852 – 1904). Married morganatically to Blanche Marconnay.
* Maria Immacolata Luisa of Bourbon-Two Sicilies (1855 – 1874). Married Enrico Prince of Bourbon-Parma, Count di Bardi.
* Gennaro, Count of Caltagirone (1857 – 1867)."