I Became the Founding Wholesale Tycoon in Ancient Times

The heroine, a graduate of a third-rate college, wakes up in ancient times in the body of an unmarried woman who has been violated. To save her younger brother's life, her aunt-by-marriage sells her into a remote mountain village where men share wives. No bizarre relationships, no romance, a space ability that appears fairly late, natural disasters in the later story, and a focus on making money. To avoid being forced to share a husband, she makes the most of the mountains around her. Though socially anxious by nature, she leads the whole village to prosperity just to survive. She starts a wholesale business in ancient times and rises from commoner to a lady granted an official title. She invents paper and makes writing paper and brushes affordable, bringing the cost of education for poor students down to an all-time low. Her unintentional aid to them earns her the praise of scholars across the land, but also draws her into the power struggle between factions in the imperial court. When natural disasters strike, she saves the people through her own efforts. Though all she wants is to lie flat and avoid the court's power struggles, she cannot escape being hunted by the powerful. To survive a second time, she personally helps the child she adopted ascend the throne.