Russian Kamila Valieva has been through a mental and physical test that few 15-year-old girls will ever face, from figure skating trailblazer to lightning rod for doping criticism at the Olympics. As the world’s attention is drawn to the elfin teen, awkward concerns abound about the sport, including whether the minimum age for contestants, which is now 15, should be raised. On Tuesday, American Mariah Bell competed in the women’s singles and as she walked off the ice, she made a dig at minors participating on the largest platform. When questioned if the age limit should be 17, the 25-year-old …