When Miranda Lambert opened for Merle Haggard recently in Sweet Home, Ore., she had the chance to meet him, which she calls "the highlight of my life." She adds, "Getting married and giving birth will both take a backseat to this event. This is always going to be the No. 1 thing that has happened to me in my whole life." Lambert recently taped an episode of Austin City Limits and will headline her first show at Gruene Hall, the oldest dance hall in Texas, on Sept. 2.