I remember that MC transmigrate into a body that is sister of the male protagonist. They both supported each other after their dad went to jail. In the orginal story, the male protagonist went through many hardship and had his own company. There was an outsider which I think there was three who think that the sister was hindrance to the male protagonist so they interfered causing the sister to die. I remember MC playing a piano and ML heard it.
For more details, the time MC came into the body, she was feeling dizzy or feel weak cause the body was hungry and hasn't eaten anything in a while. There is a part where MC went to talk to these girls who stole her money that was for lunch. Then she met with the brother who work at the construction. One of the outsider was this girl try to came close to MC and her friend to get closer to the brother since she know that he will be successful. Another one is this girl who was smarter to not think that getting rid of the sister gonna work cause the brother place importance on the sister. While the last one try to pretend to get lost and met MC and the brother at the brother work place. ML has a good identity and get closer to MC brother to get close to MC ever since getting to know her after hearing the piano. Anyone know?
Um im not completely sure but it might be My Whole Family Are Villain https://www.novelupdates.com/series/my-whole-family-are-villain/
It's not this novel since the novel I'm looking for is quick transmigration. The novel you mention is also one of my fav ^^