Re: a beautiful girl
"Peacock" has connotations of "pride"; "swan" would suggest a long neck. Robert Graves talks about "The wild-swan-breasted, the rose-ruddy-cheeked / Raven-haired daughters of their admiration", in one of his poems; but he had unusual tastes.
The British fauna is poor in Mammalia; most of the related metaphors are uncomplimentary. Thus a mouse is quiet; a shrew is virulent; a vixen is vicious, as is a polecat; a badger is irritatingly persistent; squirrels compulsively hide things away; weasels are sneakingly malevolent. (Pine martens seem to have no attributes.)
Sometimes attractive women with a particular facial configuration are described as "feline"; but "catty" means "given to malicious comments". Audrey Hepburn was often called fawn-like, and consequently liked to be photographed with deer. A "fox" is an obviously sexually attractive female; the expression tends to be used by middle-aged men with sports cars.
Not a professional ESL teacher.