Originally Posted by Altima of the Gates
Perhaps the word you are looking for is "demure"? I think that would be an apt word to describe her behavior and root of her issues. An overly demure, precocious girl. She has a natural charm, but hasn't "weaponized" it like a fille or femme fatale would. Not that much.
1. Modest and reserved in manner or behavior.
2. Affectedly shy, modest, or reserved. See Synonyms at shy1.
I don't think that's it. Typically, in the West the female figure has been seen as a dichotomy between the mother (faithfulness) and the whore (lasciviousness). A combination of both is a modern concept.
"Precocious" sounds a lot better, although only when viewing it as the contrast between Nadeko's somewhat childish behaviour and the relentlessness of her approach, as Nadeko is past puberty. Nowadays perhaps she can't be considered that precocious.