The Saint’s Sister Finds Happiness With a Foreign Mage

The main character, a young girl named Sherry, is an excellent "gatherer" who collects special herbs and magic stones. She became a gatherer to help her only relative, her younger sister Irene, a saint, but when Irene comes of age and is engaged, she abandons her and tells her to disappear somewhere. Sherry decides to leave her country and heads for the neighboring Rogue Kingdom, where magic is thriving. Along the way, she meets Aslan, a handsome magician from the Rogue Kingdom... This is the Cinderella story of a gathering nerd who turns her life around.

(Source: Natalie, translated)