YOU MUSTN'T JUDGE ME
In the past, Wu Jingguo and Wu Jinhai were separated by an invisible abyss. Therefore, the two must have never shared anything between them before their relationship finally improved recently.
It was predictable that Wu Jinhai also never told anything about his late mother to his half-brother. The death of the previous Empress was a tragedy that left a deep scar in his heart, and that was why it had not been easy for Wu Jinhai to share his pain with anyone over the years. Thus, it was also predictable that Wu Jinhai did not share anything related to the arrow that pierced his mother's chest and caused her death many years ago.
Wu Jinhai had never told Wu Jingguo anything about the arrow, but Wu Jinggu had once had the opportunity to hold it in his hands. Of course, it wasn't Wu Jinhai who let him hold the thing that took Luo Xiaoli's life many years ago, but one day the thing accidentally fell from Wu Jinhai's body, and Wu Jingguo happened to find it on the ground.