Chris Willman Senior Music Writer and Chief Music Critic Sierra Ferrell is bringing some goddess energy to the cover of her excellent new album, “Trail of Flowers,” and that fits. Just two albums into her career, Ferrell is already on the fast track to queenliness, if not godhood, among roots enthusiasts. In a world where a neo-bluegrass guy like Billy Strings can suddenly become a star among the kids, Ferrell may be the closest thing we have to that among female stars.