Short answers, pulled from the story.
Marie Louise was an Austrian archduchess who became Empress of the French as Napoleon's second wife from 1810 to 1814, and then Duchess of Parma from 1814 until her death in 1847. She was the eldest daughter of Emperor Francis II of Austria and a great-granddaughter of Empress Maria Theresa.
The marriage was arranged by her father Emperor Francis at the persuasion of Prince Metternich after Napoleon's failed attempt to marry Grand Duchess Anna Pavlovna of Russia alarmed Austria. Marie Louise was kept uninformed of the negotiations until Metternich told her directly, and when asked for consent she replied: "I wish only what my duty commands me to wish."
Yes. Marie Louise gave birth to a son, Napoléon François Joseph Charles Bonaparte, on the 20th of March 1811. The boy was immediately given the title King of Rome. He later became known as the Duke of Reichstadt and died of tuberculosis at the age of twenty-one in Vienna in 1832.
The 1814 Treaty of Fontainebleau made Marie Louise ruler of the Duchies of Parma, Piacenza, and Guastalla. She fell in love with Count Adam Albert von Neipperg, who had been sent by her father to accompany her and prevent her from joining Napoleon on Elba. She married Neipperg morganatically on the 8th of August 1821, three months after Napoleon's death.
Marie Louise married three times. Her first marriage was to Napoleon I in 1810. After Napoleon's death in 1821 she married Count Adam Albert von Neipperg morganatically; he died in 1829. She married a third time on the 17th of February 1834, again morganatically, to Count Charles-René de Bombelles, her Grand Chamberlain.
Marie Louise entered Parma on the 18th of April 1816 and largely left day-to-day governance to her Grand Chamberlain, who received instructions from Prince Metternich. She granted amnesty to dissidents after the 1831 Carbonari uprising, and her third husband Charles-René de Bombelles thoroughly reformed the duchy's finances during his time as Grand Chamberlain.