A sportswear set for girls in size 128 typically fits children aged 7-8 years old. These sets usually include a top and bottom, designed for various athletic activities such as running, gymnastics, or general play. When choosing a set, consider the material's breathability and comfort. Look for fabrics like cotton blends or moisture-wicking synthetics. Ensure the set provides a good fit that allows for freedom of movement. Popular retailers and online stores offer a wide variety of colors and styles to suit every taste.