Learn English – nother word for unpreparedness

You could just say "wet". This tends to be accepted in the English language quite happily, even when snowing as it still contains moisture.

Alternatively you could say "bad" which is often associated with wet weather.

You can't throw a bunch of adjectives together and expect English to cough up some magic word. It might happen, but then again, it might not.

If you want to focus on her beauty, use

beautiful, attractive, appealing, charming

If you want to focus on her appearance, you could try

classy, elegant, sophisticated... or even resplendent (depending on the case)

For confidence, try

poised, self-assured

Modesty, in some senses, goes against confidence, but you can use

self-effacing, unpretentious

For understated sexuality in particular, I'm partial to

elegant

(of people or their behaviour) attractive and showing a good sense of style

or, in extreme cases

sensuous

Attractive or gratifying physically, especially sexually:

_[Oxford]

PS - In my humble opinion as a reader, I like writers to describe girls with as many specific adjectives as possible, rather than be too laconic about it. Even your description in the post would mean more to a girl than any single word could.