The moment Dian gets hold of the gun, she threw a bullet right through Willow's direction. The little girl who was doing her best to hold on tight, despite the injury and fear she had, managed to evade all of Dian's shots. The metal she was holding was a few meters below the surface of the bridge and despite the fact that the second miss knew how to fire a gun, her shots weren't as accurate as Dannah's thankfully.
"No! No please!" Wolfe saw his sister's struggle and although she was lucky to evade the bullets, she was left holding the metal with one hand. Willow with thorough determination tried to reach her other hand back to the metal, but Dian continually fired shots at her. Her continual shots dried her bullets so she had to reload them outright.