FORT WORTH, Texas — Watching Coco Gauff play tennis you could easily forget that she’s basically a high school kid who should be preparing for her senior prom, and filling out college applications. She’s 18 years old, already one of the best players in the world, and an adult. She is the product of a system, and a society via technology and exposure to more media, that unintentionally turns a kid into an adult faster than previous generations. Coco is in Fort Worth to play the WTA Finals at Dickies Arena; she earned the spot as a result of being ranked as one of the top eight players in the wo…