Hubertus, Hereditary Prince of Saxe-Coburg and Gotha
Hubertus Michael, Hereditary Prince of Saxe- Coburg and Gotha, Duke of Saxony( born 16 September 1975) is the heir- apparent of the head of the family which ruled the Duchy of Saxe- Coburg and Gotha until 1918.
Andreas, Prince of Saxe-Coburg and Gotha
Andreas, Prince of Saxe- Coburg and Gotha, Duke of Saxony( given names:" Andreas Michael Friedrich Hans Armin Siegfried Hubertus"; born 21 March 1943) has been the head of the House of Saxe- Coburg and Gotha since 1998.
He is the grandson of Charles Edward, the last ruling duke of Saxe- Coburg and Gotha.
Kelly Rondestvedt
Kelly, Hereditary Princess of Saxe- Coburg and Gotha, Duchess of Saxony( born Kelly Jeanne Rondestvedt on 10 January 1975) is an American investment banker.
Through her marriage to Hubertus, Hereditary Prince of Saxe- Coburg and Gotha, the heir apparent to the defunct ducal throne of Saxe- Coburg and Gotha, she is a princess of the House of Saxe- Coburg and Gotha.
Friedrich Josias, Prince of Saxe-Coburg and Gotha
Friedrich Josias, Prince of Saxe- Coburg and Gotha( Friedrich Josias Carl Eduard Ernst Kyrill Harald; 29 November 1918 – 23 January 1998) was the head of the Ducal Family of Saxe- Coburg and Gotha and titular Duke of Saxe- Coburg and Gotha from 1954 until his death.
Prince August Leopold of Saxe-Coburg and Gotha
Prince August Leopold of Saxe- Coburg and Gotha( December 6, 1867 – October 11, 1922), known in Brazil as Dom Augusto Leopoldo, was a prince of the Empire of Brazil and of the House of Saxe- Coburg and Gotha- Koháry.
He was the second of four sons born to German Prince Ludwig August of Saxe- Coburg and Gotha and Princess Leopoldina of Brazil.
The second grandson of the Emperor Pedro II, the prince was, for some years between the presumptive heirs to the Imperial Crown of Brazil.
Their descendants would form the Saxe- Coburg and Gotha branch of the Imperial House of Brazil.
Alfred, Duke of Saxe-Coburg and Gotha
Alfred( Alfred Ernest Albert; 6 August 184430 July 1900) reigned as Duke of Saxe- Coburg and Gotha from 1893 to 1900.
He was the second son and fourth child of Queen Victoria of the United Kingdom and Prince Albert of Saxe- Coburg and Gotha.
He was known as the Duke of Edinburgh from 1866 until he succeeded his paternal uncle Ernest II as the reigning Duke of Saxe- Coburg and Gotha in the German Empire.
Princess Teresa Cristina of Saxe-Coburg and Gotha
Princess Teresa Cristina of Saxe- Coburg and Gotha( 23 August 1902 – 24 January 1990), was a German princess of the House of Saxe- Coburg and Gotha.
Princess Amalie of Saxe-Coburg and Gotha
Princess Amalie of Saxe-Coburg and Gotha (Marie Luise Franziska Amalie; 23 October 1848 – 6 May 1894) was a Princess of Saxe-Coburg and Gotha by birth and a Duchess in Bavaria through her marriage to Duke Maximilian Emanuel in Bavaria.
Amalie was the fourth child and second eldest daughter of Prince August of Saxe-Coburg and Gotha and his wife Princess Clémentine of Orléans.
Her youngest brother was Ferdinand I of Bulgaria.
Princess Dorothea of Saxe-Coburg and Gotha
Princess Dorothea Maria Henriette Auguste Louise of Saxe-Coburg and Gotha (30 April 1881 – 21 January 1967) was a princess of Saxe-Coburg and Gotha  by birth and the duchess of Schleswig-Holstein  through her marriage to Ernst Gunther, duke of Schleswig-Holstein.
Dorothea was born in Vienna, Austria, the second child and only daughter of Prince Philipp of Saxe-Coburg and Gotha and Princess Louise of Belgium.
Duke Maximilian Emanuel in Bavaria
Duke Maximilian Emanuel in Bavaria, full German name
: "Maximilian Emanuel, Herzog in Bayern" (7 December 1849 in Munich, Kingdom of Bavaria – 12 June 1893 in Feldafing, Kingdom of Bavaria) was a Duke in Bavaria and member of the House of Wittelsbach.
Maximilian Emanuel was the tenth and youngest child of Duke Maximilian Joseph in Bavaria and his wife Princess Ludovika of Bavaria.
Maximilian Emanuel was the brother of Elisabeth of Bavaria, Empress of Austria and Queen of Hungary.

Question: Who is the father-in-law of Princess Amalie Of Saxe-Coburg And Gotha?
Answer: Duke Maximilian Joseph in Bavaria