Prince Alfonso, Count of Caserta
Prince" Alfonso", Count of Caserta( 28 March 1841 – 26 May 1934) was the third son of Ferdinand II of the Two Sicilies and Archduchess Maria Theresa of Austria.
He was pretender to the throne of the Two Sicilies in succession of his older half- brother, Francis II of the Two Sicilies.
He was succeeded by his eldest son, Ferdinand Pius.
Maria Theresa of Austria-Este (1849–1919)
Maria Theresa of Austria-Este (Maria Theresa Henriette Dorothee; 2 July 1849 – 3 February 1919) was the last Queen of Bavaria.
She was the daughter and only child of Archduke Ferdinand of Austria-Este and his wife, Archduchess Elisabeth of Austria.
Archduchess Maria Theresa of Austria (1845–1927)
Archduchess Maria Theresa of Austria (15 July 1845 – 8 October 1927) was a member of the Austrian house of Habsburg-Lorraine.
Princess Maria Pia of Bourbon-Two Sicilies (1849–1882)
Maria Pia of the Two Sicilies (2 August 1849 – 29 September 1882) was a Princess of the Two Sicilies and titular Duchess consort of Parma as the wife of Robert I, Duke of Parma.
Maria Pia was the daughter of King Ferdinand II of the Two Sicilies and his wife, Maria Theresa of Austria.
Maria Pia was forced into exile along with the rest of her family after the unification of Italy in 1861.
Archduke Joseph Franz of Austria
Archduke Joseph Franz Leopold of Austria( 9 April 1799 – 30 June 1807) was the second son and seventh child of Francis II, the last Holy Roman Emperor and his second wife, Maria Theresa of Naples and Sicily, daughter of Ferdinand I of the Two Sicilies and his wife Maria Carolina of Austria.
He was their fourth child to die.
Princess Maria Luisa of Bourbon-Two Sicilies
Princess Maria Luisa of Bourbon- Two Sicilies( full Italian name:" Maria Luisa Immacolata di Borbone, Principessa di Borbone delle Due Sicilie")( 21 January 1855, Naples, Two Sicilies – 23 August 1874, Pau, Armagnac, France) was the youngest daughter of King Ferdinand II of the Two Sicilies and his wife Archduchess Maria Theresa of Austria.
She was known for her piety and for her charity to the poor.
Princess Henrietta of Nassau-Weilburg
Henrietta Alexandrine Friederike Wilhelmine of Nassau-Weilburg, then of Nassau
(areas now part of Germany) (30 October 1797 Palace Ermitage, Bayreuth – 29 December 1829, Vienna) was the wife of Archduke Charles, Duke of Teschen.
Her husband was a notable general of the Napoleonic Wars and victor of the Battle of Aspern-Essling against Napoleon I of France.
Prince Gaetan, Count of Girgenti
Prince Gaetan of the Two Sicilies, Count of Girgenti( 12 January 1846, Naples, Two Sicilies – 26 November 1871, Lucerne, Switzerland) was the seventh child of Ferdinand II of the Two Sicilies and his wife Maria Theresa of Austria.
Gaetan was a member of the House of Bourbon- Two Sicilies and consort to Isabella, Princess of Asturias, twice the recognized heir presumptive to the throne of Spain.
Through this union, Gaetan was created an Infante of Spain.
Princess Maria Immaculata of Bourbon-Two Sicilies (1844–1899)
Princess Maria Immaculata of Bourbon- Two Sicilies( Full Italian name:" Maria Immacolata Clementina, Principessa di Borbone delle Due Sicilie")( 14 April 1844, Naples, Kingdom of the Two Sicilies – 18 February 1899, Vienna, Austria) was fifth child and second- eldest daughter of Ferdinand II of the Two Sicilies and his wife Maria Theresa of Austria.
Through her marriage to Archduke Karl Salvator of Austria, Maria Immaculata became an Austrian Archduchess.
Maria Theresa of Austria (1816–1867)
Maria Theresa of Austria (Maria Theresia Isabella; 31 July 1816 – 8 August 1867) was the second wife of Ferdinand II of the Two Sicilies.
She was the eldest daughter of Archduke Charles, Duke of Teschen and Princess Henrietta of Nassau-Weilburg.
Her paternal grandparents were Leopold II, Holy Roman Emperor and Maria Luisa of Spain.
Her maternal grandparents were Frederick William of Nassau-Weilburg (1768–1816) and his wife Burgravine Louise Isabelle of Kirchberg.
Maria Theresa was Princess-Abbess of the Theresian Royal and Imperial Ladies Chapter of the Castle of Prague (1834-1835).

Question: What nationality is Maria Theresa Of Austria (1816–1867)'s mother?
Answer: Germany