No sooner had Doris Roberts received the Sunday night salute to her achievements in 50-years plus in the biz when she took off for D.C. and spoke today at the Reagan building for the AARP to an audience of 500. Roberts, 77, said her talk is “inspirational — not religious.” It’s her fifth AARP appearance and she has no intention of retiring from speaking or acting. She has two projects awaiting the WGA strike settlement. In one of the films, she plays head nurse in a retirement home. In the second, “The Matchmaker,” she’s a mother who discovers her son is gay. It’s serious comedy — a Doris forte.