On 18 September 1718, Maria Theresa was joined in the nursery by a younger sister named Maria Anna. She would be the only one of three of Maria Theresa’s siblings who would survive to adulthood. An elder brother named Leopold died on 4 November 1716, not even one year old and younger sister Maria Amalia died on 19 April 1730 at the age of 6. Her birth was a disappointment as she had not been the longed-for male heir, but Maria Theresa adored her little sister. The two sisters were raised together.
By 1725, negotiations were already underway for a marriage with Philip, Duke of Parma. The groom in question was also just five years old, but in the end, Maria Anna fell in love with Charles Alexander of Lorraine, who was the younger brother of Francis of Lorraine, Maria Theresa’s husband. The wedding took place at the Augustine Church on 7 January 1744. The couple were then appointed governors of the Austrian Netherlands to succeed Maria Elisabeth of Austria, who had died in 1741. They settled in Brussels, but only had two months together before Charles Alexander was off to fight in the war against Prussia. By then, Maria Anna was already pregnant.
Maria Anna delivered a stillborn child on 1 December 1744 and never recovered. She died two weeks later on 16 December. Maria Theresa wrote to the Dutch physician who had attended her sister during those two weeks, “I can discern the Will of the Almighty. In His Grace, he keeps me alive to tread the path of trial and grief that He has designed for me. Throughout the great adversities, I have encountered in my reign, the thought of establishing these two families, who would support each other, was my sole comfort.” [ref] Robert Pick – Empress Maria Theresa p.138 [/ref]
Maria Anna and her stillborn child were taken to Vienna to be buried in the Imperial Crypt.