I assumed and wrongly so that Ji Soo became a reporter to follow in her father's footsteps, clear his name, vindicate him, and maybe she did subconsciously but didn't realize it until now. She may have joined Daily Korea to get closer to JH and prove how trashy of a reporter he is mostly to himself, but that's slowly changing because, as they say, nothing ever really goes exactly as planned; that's why it's a plan, not a certainty.
I admired how JH turned the tables on her and got her assigned to City Desk to teach her the reality of how journalism works, that news is a business that can change based on perceptions that often become a reality, and that sadly the press corrupts itself. I loved that the lesson worked and that Ji Soo finally told JH her true identity. Maybe now she can start focusing on her strength rather than her pain. And together, they can become the change they want to see.