When she was young, the future Queen Consort of France did not like to study. As noted by Antonia Fraser, in Marie Antoinette, The Journey:
The trouble was that this affable little creature had managed, it seemed, to avoid more or less the unpleasant experience of education, other than in the arts where her skill in dancing and her taste for music added to her general aura of grace. (Fraser, page 31.)
Writing slowly, and reading as infrequently as possible, the young archduchess had trouble concentrating, leading to future difficulties in France:
The real betrayal in Marie Antoinette’s education was that she was never encouraged to concentrate. This ability, comparatively easy to inculcate in childhood, was generally held to be lacking in Marie Antoinette the adult, even by her admirers; her conversation tended to be disjointed “like a grasshopper,” wrote a member of her intimate circle. Madame Campan, the First Lady of the Bedchamber, who knew her so well, was eager to point out that the problem was not actually lack of intelligence. What Marie Antoinette knew, she knew - or rather what she had been properly taught. (Fraser, page 33.)
The Habsburgs, who occupied various thrones of Europe for centuries, had a genetically transmitted condition visibly affecting the lower lip of many family members. Marie Antoinette was one of them.
Charles II of Spain (1661-1700) likely had the worst form of “dropped lip,” but it is also visible in the portraits of Maximilian I (1459-1519), Charles V (1500-1558), and Philip IV of Spain (1606-1665), among others.
Artists who painted Marie Antoinette’s portraits often seemed to ignore - or minimize - the condition (largely by avoiding her profile). Sculptors created a more accurate likeness, as did Madame Tussaud in her death mask of the queen.
By the time Antoinette was old enough for her mother to arrange a marriage with the future Louis XVI, Antoinette’s father had been dead for several years. (He had died suddenly - on the 18th of August, in 1765 - while returning home from the opera in Innsbruck.)
Perhaps he might have cautioned against the match, but who could have predicted that a member of the Habsburg imperial family would lose her head in France?