Short answers, pulled from the story.
Maria Theresa was the ruler of the Habsburg monarchy from 1740 until her death on the 29th of November 1780, and the only woman to hold that position in her own right. Her territories included Austria, Hungary, Bohemia, Croatia, Transylvania, the Austrian Netherlands, and numerous other lands. By marriage to Francis Stephen, she was also Holy Roman Empress.
Her father Charles VI spent his entire reign securing the Pragmatic Sanction of 1713 to allow female succession, but left Austria with only 100,000 florins in the treasury and an army reduced to roughly 108,000 men. Upon his death in October 1740, Saxony, Prussia, Bavaria, and France all repudiated the sanction they had previously recognised, and Frederick II of Prussia invaded the wealthy province of Silesia within months.
On the 11th of September 1741, Maria Theresa appeared before the Hungarian Diet wearing the Holy Crown of Hungary and spoke in Latin, declaring that the existence of the kingdom and her own person were at stake. She held her infant son Joseph while weeping and placed the future king under the protection of the Hungarians. Despite initial hostility from the Diet, her speech won their support and the declaration that they would die for her.
Maria Theresa established mandatory secular primary schools for all children of both sexes aged six to twelve, with a curriculum focused on reason, social responsibility, and multilingual instruction. The reforms, shaped by Silesian school reformer Johann Ignaz von Felbiger and made law by December 1774, included teacher training colleges and prizes for able students. In the Archdiocese of Vienna, school attendance rose from 40% in 1780 to 94% by 1807.
After losing multiple family members to smallpox and contracting the disease herself in 1767, Maria Theresa ordered inoculation trials on over 100 orphan children, overriding the objections of her own physician Gerard van Swieten. The trials proved successful, and she subsequently had herself and two of her children inoculated. She hosted a dinner at Schonbrunn Palace for the first sixty-five inoculated children, waiting on them herself.
Maria Theresa doubled state revenue from 20 to 40 million florins between 1754 and 1764. By 1775, the Habsburg monarchy achieved its first balanced budget, and state revenue reached 50 million florins by 1780. Friedrich Wilhelm von Haugwitz funded a standing army of 108,000 men through 14 million florins from crown lands and introduced taxation of the nobility for the first time.