NJERI MWANGI  KEYSHA Atiki is only 10 but she can already lift her own weight as she trains with a weightlifting coach who once competed in the Olympics - her grandmother. Mercy Obiero was only the second African woman to compete in weightlifting at the Olympics, representing her native Kenya in 2012. Now retired from professional competition, the 42-year-old works as a coach, and both her daughter and granddaughter are hoping to follow in her footsteps. "I feel very happy and proud to be training my daughter and granddaughter at the same time," Obiero told Reuters at her house in…