Court documents allege the younger women "actively suppressed evidence" by transporting and concealing a firearm at an associate's property in order to help someone avoid conviction.
Tongia, 33, was found dead in his Karori home late last month.
Loved ones of Tongia and supporters of the defendants sat in the public gallery, after spending the morning waiting for the appearances.
The woman cannot yet be named, and lawyers have indicated there will be an application for name suppression.
As the younger woman was led from the court her loved ones blew kisses and called out "love you".
Despite the murder charge, police are still appealing to the public for any information.
"The investigation is still active and police would still like to hear from anyone who has information which may assist," a statement said this morning.
"Police are not ruling out the possibility of further charges."
Anyone who may have seen or heard anything suspicious in the early hours of Sunday, December 20, and who has not spoken with authorities is urged to contact police immediately via 105.
Police revealed yesterday that they had located a firearm they believed was linked to his death.
The firearm was found during a search warrant in Wilton earlier this month, police said.
"It is currently undergoing forensic analysis."
Police said they are also looking into whether or not the weapon is linked to any other offending across the district.
"While testing is underway, police [are] unable to provide further information about the firearm," police said.
"No one should have to put up with this activity in their neighbourhood and we will continue to target those involved in violent offending."
