It is common in informal speech and writing but is neither rare nor wrong in serious discourse. There are 20 meanings listed in oed's entry for the word pretty, four of which are labelled obsolete Pretty (comparative prettier, superlative prettiest) pleasant to the sight or other senses
Sensual attractive pretty nude girl posing | Stock image | Colourbox
Attractive, especially of women or children
[from 15th c.] coordinate term, near synonym quotations coordinate term
We can use pretty as an adverb, before an adjective or another adverb, meaning ‘quite, but not extremely’ … that's a pretty hat you're wearing The sofa was covered in very pretty flowery material She's got such a pretty daughter
She looked pretty in a simple cotton dress. Pleasing or attractive to the eye, as by delicacy or gracefulness. See examples of pretty used in a sentence. If you describe someone as pretty, you mean that they are attractive
She's a very charming and very pretty girl.
Use the word pretty to describe something with a delicate and pleasant appearance Something that’s pretty is less powerful and intimidating than something that’s beautiful, the way a pretty floral raincoat is less intimidating than a beautiful film star. In a delicate or graceful way Pleasing or charming but not grand or overwhelming
A pretty little cabin in the woods.
