Walking into Sarah Williams’ show “Pretty Rural” at Andrea Schwartz in San Francisco, viewers are teleported across the country by her newest paintings. Specifically, they are transported into a dark winter evening complete with Christmas lights in Brookfield, Missouri, where Williams grew up. The double entendre is immediately clear. “Pretty Rural” is both extremely rural and exquisitely gorgeous. Williams masterfully documents scenes of houses and yards in small-town Middle America with a painterly romanticism and a hefty dose of reality.