On the latest episode of the MBC drama "Man Who Dies to Live", Lee Ji-yeong B (Lee So-yeon) knew she wasn't the count's (Choi Min-soo) daughter but pretended to be.
She knew she wasn't his daughter when she saw the picture he had. However, he was filthy rich and she wanted to use him. She pretended to be married to Kang Ho-rim (Sin Seong-rok). Kang Ho-rim also had to do this to keep the money the count gave him for his business.
Choi Min-soo however, started to be suspicious of Lee Ji-yeong B and looked for the orphanage where she supposedly was. Lee Ji-yeong B and Kang Ho-rim stopped him with lies.