Forgetting the past is possible but not easy. Let alone bad events, violence, or sexual harassment. Once the person is subjected to such painful event's it's not easy to go back to normal. It's like something was broken and never going to be fixed again no matter how hard you tried to repair it.
In Pearl's case, the only difference is. That she found true love. A man who loves despite knowing everything about her. He saved her life and pulled her out of the hall where she was living every day and every night in that place. Her life changed for the better and now she was carrying a child. The fruit of their love. But She wasn't happy and she doesn't even know why.
I placed Petal outfit image in the comments