The judge granted the Crown request to dismiss charges against Tove Paranihi in the Christchurch District Court on Tuesday.
The shooting in Kaiapoi on January 4 left Fairmont Wiringi, the son of a Mongrel Mob leader, seriously injured.
Wiringi's father Joseph is a Mongrel Mob president and his brother Fairlane is also a patched member of the gang.
Mokonuiarangi Chong and Jarrad Singer face joint charges, including unlawful possession of weapons, and failing to stop for police.
Singer was hospitalised with a gunshot wound, and is due in court on January 19.
Police were called to the incident after a man arrived at a residence in Kaiapoi in the early hours of the morning on January 4, seeking help after being shot in the arm.
The man was taken to Christchurch Hospital by ambulance in a serious condition.
The shooting came just days after Christchurch man Kane Wayman - an associate of the Head Hunters gang - was killed.
Wayman had attended a New Year's Eve party at the headquarters of rival gang Mongols MC.