I came across some information on the 4 eldest daughters of Maria Theresia and Franz Stephan, especially on Maria Elisabeth (1737-40) and Maria Carolina (1740-41), who died early....
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Maria Elisabeth was a cheerful and lively girl, the joy of her grandfather Emperor Charles VI. He liked playing with his "Spring Waltz". When the family was in Laxenburg on the 7th June 1740, Maria Elisabeth suddenly started to vomit. Throughout the day, stomach cramps and vomiting alternated.
On the same evening at nine clock, Maria Elisabeth, aged 3, died in the arms of her father Franz Stephan. He wrote about the death of his daughter: "At eight clock, they called me and handed me a note from the doctor, from which I took, 'It is time that you come to carry away your wife, because the child will not live long'. A little confused I went away and when I arrived, my wife was quite dissolved in tears. I took her by the hand and led her to her apartments. Then I went back to the patient. She fell back and died in my arms."
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Maria Anna was the second child of Maria Theresa. She was later called "Marianna" or "Mariandl". Little is known about her first two years of life. When her brother Joseph on 13 March 1741 came to the world, her older sister Maria Elizabeth and her younger sister Maria Carolina, already passed away. From then on it was all about the long-awaited successor to the throne. Marianna was hardly noticed. There were only two great performances that they put the child in the immediate center of attention. These were the two coronations of Maria Theresia as Queen of Hungary in 1741 and Queen of Bohemia in 1743.
In the two subsequent years by two other highly successful competitors for her mother's affections: Maria Christina (Mimi) and Maria Elizabeth (Liesl). Marianna had a soft body and a nice hands, but her face was soon hard and angular. She saw herself as very similar to her father, who was generally described as good-looking man.
She was versatile (multi-talented), her dancing was also to above-average in skill. In the studies, she was eager and more focused than most of their siblings. Particularly striking was her phenomenal memory .
In the ever-growing crowd of children, there were rivalries and taunts. Their prime target was Marianna. In the competition for the love of their mother Marianna always drew short. Joseph had a special position because he was the heir, but also against Mimi and Liesl Marianna she wasn't loved as much. Liesl was indeed flirtatious and superficial, but so (unearthly/superlatively?) beautiful that everyone was fascinated by her.
Mimi's appearance was not so overwhelming, but it was cute and cuddly, and endowed with feminine wiles. The mother was so besotted with her, that Mimi virtually got away with anything, what with the others were strictly prohibited.
Marianna from the third year of her life - after the birth of his brother Joseph - what the Viennese called an "invalid"" onwards. There was no winter without coughing. Maria Theresa hardly mentioned her advantages/talents in her correspondence, but always her physical ailments.
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On 12th January 1740 , just five days after the death of the eldest child Maria Elisabeth, Maria Theresa brought her third child, Maria Carolina, into the world. But this child's life was not long. At 12 months old, her little Highness suddenly and unexpectedly (on 24 January 1741) had an illness. About noon the following day, Maria Carolina died. During the autopsy of the corpse, there was none found either in the head or something within the body, which can cause a sudden death. In her stomach, there was only a little nurse's milk.
The cause: Lack of vitamin D
As children's seizures or convulsions were referred to then cramping (convulsive) seizures in children. It is an overexcitability of the nervous system caused by the disturbance of calcium and phosphorus metabolism due to a lack of vitamin D.
The other siblings had better luck.
The small children in that time were always wrapped securely and protected from light and sun as possible, suffered a lot because of this deficiency. In the following years, three more children suffered from convulsions. Favorite daughter, Maria Christina, got the disease - also accompanied by fever - at the age of seven. Archduke Ferdinand became ill in May 1755 in the age of one year, but survived the convulsions rapidly. Months later, it hit eight-year Leopold. They wrote his complaints, however, a repletion, that plethora, and overloading of the stomach. He also got lucky. The symptoms disappeared after a few days.
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On the anniversary of their mother, 13 May 1742, Maria Christina, known as Mimi, was born. Within the family, she was noted for her beauty and intelligence.
Like all children of Maria Theresa, Mimi was brought up very religiously. Daily morning and evening prayers had Mimi kneeling, confession and communion were prescribed at least once a month and fasting was strictly adhered to. Also, learning languages was important for the children. In Italian and French Marie Christine made great progress. In music, Mimi showed no special talent, but she had talent for drawing and painting.
From childhood, Marie Christine gained the full affection of their mother. It was criticized by Maria Theresia much less harshly and (less) insultingly than her siblings: "... I'm quite happy with your letters, but your spelling is too flighty. It must be uniform and not be in a hurry in writing, you (have) to look how the beginning is very different from the end. "
At 18, Marie Christine got her own household under the direction of the High Steward, Count Losy Losynthal. About this time began her enthusiastic friendship with Isabella of Parma, the first wife of Joseph.
