NASHVILLE, Tenn. (AP) _ Kellie Pickler is performing in the nation's capital today. She's singing at an event called the AARP GrandRally at the U.S. Capitol. The gathering highlights the plight of grandparents raising their grandchildren. Pickler was raised by her grandparents. She'll perform ``My Angel,'' a song on her debut album that she wrote about her grandmother. Pickler's also donated nearly $50,000 to AARP's Grandparenting Foundation.