Question: Who is the mother-in-law of Francesca Von Habsburg?

Knowledge 1: Francesca von Habsburg
Francesca von Habsburg-Lothringen (born 7 June 1958) is an art collector and the estranged wife of Karl von Habsburg, current head of the House of Habsburg-Lorraine. [SEP] Knowledge 2: Karl von Habsburg
Karl von Habsburg (Karl Thomas Robert Maria Franziskus Georg Bahnam; born 11 January 1961), also known as Karl of Austria and referred to by his ancestral titles as Archduke of Austria, Royal Prince of Hungary, Bohemia and Croatia, is an Austrian politician, the current head of the House of Habsburg-Lorraine which ruled the lands of the Habsburg Monarchy, the Empire of Austria, the Austro-Hungarian Monarchy, and the Kingdom of Hungary as well as the Crown lands of Bohemia and Croatia by hereditary right until the end of World War I. Born in Starnberg, Germany, in 1961, he is the son of Archduke Otto von Habsburg, Crown Prince of Austria and Princess Regina of Saxe-Meiningen, and the grandson of the last Austrian emperor, Charles I.He served as a Member of the European Parliament for the Austrian People's Party 1996–1999.Like his father, he is known as an advocate for the Pan-European movement.
Knowledge 1: Karl von Habsburg
Karl von Habsburg (Karl Thomas Robert Maria Franziskus Georg Bahnam; born 11 January 1961), also known as Karl of Austria and referred to by his ancestral titles as Archduke of Austria, Royal Prince of Hungary, Bohemia and Croatia, is an Austrian politician, the current head of the House of Habsburg-Lorraine which ruled the lands of the Habsburg Monarchy, the Empire of Austria, the Austro-Hungarian Monarchy, and the Kingdom of Hungary as well as the Crown lands of Bohemia and Croatia by hereditary right until the end of World War I. Born in Starnberg, Germany, in 1961, he is the son of Archduke Otto von Habsburg, Crown Prince of Austria and Princess Regina of Saxe-Meiningen, and the grandson of the last Austrian emperor, Charles I.He served as a Member of the European Parliament for the Austrian People's Party 1996–1999.Like his father, he is known as an advocate for the Pan-European movement. [SEP] Knowledge 2: Francesca von Strassoldo Grafenberg
Francesca von Strassoldo Grafenberg was a Countess of Carniola Slovenia.She was born January 3, 1781, in Tržič.In 1798, she married the Bohemian nobleman and Austrian field marshal Joseph Radetzky von Radetz.The couple lived together on the former estate of Francesca's mother until 1819.The two had five sons and three daughters.She died January 12, 1854.
Knowledge 1: Francesca von Habsburg
Francesca von Habsburg-Lothringen (born 7 June 1958) is an art collector and the estranged wife of Karl von Habsburg, current head of the House of Habsburg-Lorraine. [SEP] Knowledge 2: Francesca von Strassoldo Grafenberg
Francesca von Strassoldo Grafenberg was a Countess of Carniola Slovenia.She was born January 3, 1781, in Tržič.In 1798, she married the Bohemian nobleman and Austrian field marshal Joseph Radetzky von Radetz.The couple lived together on the former estate of Francesca's mother until 1819.The two had five sons and three daughters.She died January 12, 1854.

Answer: Princess Regina of Saxe-Meiningen