Actually, when Madam of Prime Minister first discovered it, she intended to sell her off, but unfortunately, she realized it too late. Not only did she fail to sell her, but she also almost got Prime Minister Shen to divorce his wife.
Prime Minister Shen was relatively kind to her. He thought that if she were made a concubine, she would be controlled by Madam of Prime Minister, so he made a change, allowing her to become a young lady of the mansion, and publicly declared that she was born to Madam of Prime Minister but was raised elsewhere when she was young. This claim nearly infuriated that old woman to death.
However, that old woman was somewhat cunning. When she couldn't do anything about them, she suggested to the Prime Minister that since she was now a young lady of the mansion and of age, they should arrange a marriage for her to avoid public gossip.
