looking for webtoon-manhwa

FL is adopted as a playmate for the young lady (sick with many admirers). the young lady passed away and the FL left the family despite the family thought of her as part of the family. after FL left the house, the family adopted another daughter (ogFL) who looked like the dead young lady, and the admirers all chased after her except ML. ML found FL and made a deal with her for her debut to society as part of his promise with the dead lady. FL agree to the deal in exchange for reading the letter wrote by the dead lady to ML.