I was talking about Maria Carolina's long-terms prospects had she stayed in Vienna and not married abroad, not about how young she was when she married; I know that fact already and did not ignore it. Please just answer the possible scenarios had she stayed in Vienna - what would've been her marriage prospects there, possible posts, role at court? Does anyone think she could've done better than her older sisters Maria Anna, Maria Christina, and Maria Elisabeth, who all stayed in Vienna and/or near it? Especially Marianna and Elisabeth, who did not marry, and did not have any influence at court and consigned to the single life. Elisabeth certainly wanted to marry, despite having the smallpox.
Is reading books is an indicator of high intelligence? I think it just shows that a person is curious and wanted to learn and/or at least to improve one's mind. You keep on mentioning about how MC was one of the more intelligent daughters of Maria Theresa, what's the proof of that besides her love of reading (in itself not a clear indicator of high intelligence). Unless there was some sort of I.Q. tests back then.... or records of MC's stellar academic performance while in Vienna. To be frank, only Marianna seems to have clear evidence of high intelligence among the sisters because her scientific studies point to that.
There is evidence that MC was only nice - and even pretended to be passionately in love with him - to Ferdinand at first because she wanted to gain his confidence. Even quite fawning books (The Queen of Naples and Lord Nelson, A Sister of Marie Antoinette) on her point to that. Yes, her sister Maria Amalia wasn't very nice to her Ferdinand at first. She was wrong in that but at least she never seemed to deceive him, like MC did to her Ferdinand, about her feelings. Amalia also realized that she made mistakes with her husband, made up for it, and tried to see her husband in a better light (if she didn't, she never would've declared that she loved him very much and make concessions in her marriage). That is the difference betweeen the two sisters, proud as they both were, and which I think spelled the difference in the long run in their respective marriages (not that Amalia had a perfect relationship with her Ferdinand).
Yes, MC loved Austria so much she declared that the death of her imbecile (her own words, not mine) sons is no big loss and then she'd marry her eldest girl to her brother (Joseph? who declared he wouldn't marry for the 3rd time; how irrational of her) and just take Naples back home with her to Austria. I think that is yet another reason why she failed as a ruler -- a good ruler should at least love her domain and her people. Honestly, she could've done much better in politics and in her personal life because she did have great energy, was willful (I mean to use this trait in a constructive way), capable of ruling, undertook necessary reforms, and was not stupid. Of course, living in the Napoleonic times was hard for all royals but there's evidence that MC's faults got the better of her good side, which led to certain sad consequences.