Help me find this manhwa please

The female lead is a poor noble’s daughter. Her father works under a higher-ranking noble family, which is also the family of her childhood friend. At some point, the FL convinces her father to buy a piece of land or a mine that looks completely worthless. Later on, it turns out that the land actually contains very valuable gems or minerals.

To develop the mine, the FL gets help from the male lead, who is a very well-known and ruthless mercenary or the leader of a mercenary guild. When the value of the land becomes public, the childhood friend’s family suddenly wants to take control of the mine and tries to persuade the father to hand it over. However, the father refuses and says that the land belongs to his daughter, not him.

After that, the father ends up being locked up or detained and can’t return home. The FL then goes to her fiancé’s family estate to rescue her father.

If anyone recognizes this story, please help me Thank you!