NAIROBI, KENYA — Speaking just after her Oct. 9 return from the funeral of 9-year-old John Ian Maina, Sally Gatei was in a reflective mood.  Gatei was in the room when a grenade exploded at about 10:30 a.m. on Sept. 30 at St. Polycarp’s Anglican Church in Kenya. The explosion killed the boy and injured eight other children. “Many Christians,…