Short answers, pulled from the story.
Désirée Clary was Queen of Sweden and Norway from the 5th of February 1818 to the 8th of March 1844, as the wife of King Charles XIV John. She was the one-time fiancée of Napoleon Bonaparte, the sister of Julie Clary who became queen consort of Spain and Naples, and the mother of King Oscar I of Sweden. She was the first commoner to become Queen of Sweden since Karin Månsdotter in 1568.
Yes. Napoleon became engaged to Désirée Clary on the 21st of April 1795, while her elder sister Julie was engaged to his brother Joseph. Napoleon broke the engagement on the 6th of September 1795 after becoming involved with Joséphine de Beauharnais, whom he married in 1796.
Désirée Clary was crowned Queen of Sweden on the 21st of August 1829, in Storkyrkan in Stockholm. The coronation was delayed for years because her husband, Charles John, feared religious complications arising from her Catholicism. She was never crowned in Norway, despite requesting it, for the same reason.
Désirée Clary married Jean Baptiste Jules Bernadotte, a French general and politician, in a secular ceremony at Sceaux on the 17th of August 1798. Bernadotte later became King Charles XIV John of Sweden. Their only child, a son named Oscar, was born on the 4th of July 1799.
Désirée Clary had a lifelong attachment to France and Paris and felt completely out of place at the Swedish royal court. She never learned to speak Swedish, struggled with formal court etiquette, and found the climate and customs foreign. She left Sweden in the summer of 1811 and did not return permanently until 1823, more than a decade later.
Queen Desideria was known for reversing her sleeping hours, typically retiring at four in the morning and waking at two in the afternoon. She kept chickens as pets at Rosersberg Palace, feared the dark but walked in the palace park at night with a lady-in-waiting dressed in white to ward off bats, and habitually arrived at the opera after the performance had ended. She called her nightly carriage circuits of the palace courtyard "Kring kring," one of the few Swedish phrases she ever used.