Tucker’s freewheeling personal life — she’s expecting her second child out of wedlock — has gotten so much press lately that nobody seems to have noticed that she has matured into a first-rate interpreter of country angst. Celebrated at 13 in the early ’70s for her huge, booming voice and the material that cast her as an underage vixen (”Would You Lay With Me in a Field of Stone”), she then grew into a sex kitten in her late teens, her appeal lying partly in her chronological poise between jailbait and adulthood. Now 32 and a single mother, Tucker finally sounds like a grown-up. In What Do I Do With Me, whether singing about emotional deprivation on such ballads as ”He Was Just Leaving,” or growling and hiccuping her way through a spirited selection of blues, rockabilly, and early Brenda Lee-style pop, she radiates the pain and pride of a woman who has lived life by her own code, for better or worse. Musically, at least, she couldn’t have made a finer choice. A