In recent years, many young people like wide and black framed glasses, so black is the most classic one. Don't wear white frame glasses and leopard is out of fashion now. geek chic glasses and retro frame are also very popular in younger girls. From the aspect of material, board will be in fashion in the flowing years.
There are many types of teenager glasses in this site. You can have a look. But if you want to buy you younger sister a pair glasses, you should also take her face shape, skin tone and hair style into consideration.
As a matter of fact, younger generations are confronted with various choices for the cool glasses. Fashion eyeglasses such as the black frame glasses, the geek eyeglasses and the cool oversized glasses are the first choices for your younger sister. If she has clear ideas about her favorite fashion style, she would be sure to get the most fashionable eyeglasses.