The Widow's Secret Gate

Autumn Quinn travels to a famine year and becomes a widow. She binds to the Dual-World Gate System, and by shuttling between the modern world and the famine year, she trades grain for old artifacts to earn money to save her Grandma and raise her two children. She drives away villains, unlocks The Black Market to trade for treasures, and finally uses her modern knowledge to help the villagers dig a well, becoming the entire village's great benefactor.