I am trying to follow everything being said about Marie Elizabeth's potential marriages. Please correct me if I am wrong.
Was she considered as a possible wife for Louis XV after Queen Marie L. died in 1768? If so, it is quite a coincidence she was born in the exact same month (one week apart) and year as Madame Du Barry, August 1743. ( who in an unofficial capacity had the same job. ) ME would have then become the grandmother in law of her own sister MA in 1770?
And the potential Polish Crown- here is where I am very confused; was she actually considered to marry Stanislaw Poniatowski- a former lover of Cathernine the Great? A daughter of Maria Theresa would be allowed to do that? Or, are we talking about one of the older brothers of MC's husband Albert of Saxony who could have possibly been a contender for the Polish crown instead of the oldest brother who had died right after his father Augustus III?.
And was the Duke of Chablais the uncle of the 2 sisters who became wives of Louis XVI's brothers? And, when it did not work out for ME to marry him, didn't he then marry his own niece, a younger sister of the two sisters?
And finally Maria Amalia's Zweibrucken- did not he end up becoming the Elector of Bavaria in 1777- the state Joseph wanted so much to become a part of the Habsburg Empire? ( Frederick the Great: "Over my dead body.") I bet Joseph would have wanted ME to be married to him at this point.
Poor Marie Elizabeth!
The widowed Louis XV was very much taken with Marie Antoinette when she arrived in France to marry his grandson, and rather fancied the idea of marrieage to her sister, writing to the marquis de Ruffec (part of his private diplomatic group) in 1770, 'Let [François-Michel Durand de Distroff, French chargé d'affaires in Vienna] take a good look at her figure, from head to foot and without leaving out anything he can see of the Archduchess Elisabeth; let him also find out about her character, all in deepest secrecy and without arousing suspicions in Vienna". However, he didn't persist with the notion - whether because he cooled with regard to Marie Antoinette, thought Maria Elisabeth's smallpox scarring was too unpleasant, or just cooled on the idea of marrying again, is not clear. So this project was never really a goer.
Stanislaw Poniatowski made matrimonial overtures to Maria Theresa for Maria Elisabeth but due to the instability of his throne and his lack of private fortune the Empress was not enthusiastic (although she did not immediately reject the offer), though when Catherine the Great learned of it she very firmly indicated she would not agree to such a marriage, and Poniatowski was too dependent on Russian backing to go against her.
Maria Elisabeth's chances as replacement for Marie Christine as wife to Benedetto Maria Maurizio, Duc de Chablais, seem to have been scuppered by the size of the establishment Maria Theresa granted to Marie Christine and Albrecht of Saxony, and Joseph's refusal to provide for another brother-in-law who was not useful in a dynastic sense, e.g. a ruling sovereign. Chablais was indeed the uncle of the Comtesses de Provence and Artois and did marry his niece Maria Anna of Savoy. They apparently had a happy marriage, though there were no children.
Joseph's grab at Bavaria would not have been improved by Maria Elisabeth's marrying the Duke of Zweibrucken and producing more heirs to Bavaria who would cut out the Habsburgs; there has been some suggestion that this is one reason he supported Maria Amalia's marriage to the Duke of Parma, to get her off the scene. So a sister married to a Bavarian would never have been a goer for Joseph until far too late.
Yes, poor Maria Elisabeth - all the matrimonial projects were a bit emphemeral. Though frankly, Queenship of France or Poland could have had rather chancy outcomes; the Duc de Chablais sounds the best candidate.