Stand out with this anniversary Roller Skate T-shirt for children. A perfect Ninth Birthday outfit for little girl to celebrate the 9 th birthday party. Let's Roll into Nine, with Unicorn Rainbow Graphic. Great Roller Derby clothing for skating rink. 9th Birthday Girls T Shirt for kids. Unique gift idea for a daughter, niece, cousin, sister or friend who turns 9 years old! Organize a Bday party, get all supplies, decorations, outfits, cake, princess donuts, candles and this cute Unicorn shirt costume.