The sisters part scenario, makes me think of Glass Slippers....
the two sisters were close and lived with their father who was exiled by his weathy grandfather. They lived a humble life as kids but their father died, then their grandfather went to look for them. The sister somehow got separated, then older sister one got back to his original wealthy family while the younger one forgot her father/sister and was adopted by a poor family who already has a daughter. The younger daughter was abused by the poor family, and years later the wealthy family tries to track down the younger sister. but there was a switch, and the daughter of the poor family said she was the long lost daughter of the wealthy family. As they grew to adults the fake younger sister makes so many plans for the real sisters to not meet or make the real younger sister look bad, and her manipulations made the older sister hate her younger sister. Anyway Thats the gist of the Glass slippers.... but but but...
BUT somehow i think there is a different more appropriate drama for what you are looking for than this drama. A drama that may have a villain like park hana. A weekday drama aired around he last 5 years.
Since glass slippers more than 10 years ago.... and is a weekend drama
