By Sean Murphy THE ASSOCIATED PRESS OKLAHOMA CITY (AP)-An iconic chief of the Cherokee Nation, Wilma Mankiller, inspired countless Native American children as a powerful but humble leader who expanded early education and rural healthcare. Her reach is now broadening with a quintessential American honor: a Barbie doll in the late Mankiller’s likeness as part of toymaker Mattel’s “Inspiring Women” series. A public ceremony honoring Mankiller’s legacy is set for Tuesday in Tahlequah in northeast Oklahoma, where the Cherokee Nation is headquartered. Mankiller was the nation’s first female principal chief, leading the tribe for a decade until 1995. She focused on improving social conditions through consensus and on restoring pride in Native heritage. She met with three U.S. presidents and received the Presidential Medal of Freedom, the nation’s highest civilian award….