Two men from the car, Clarke McCallum and Daniel Rippon, assaulted Mr Kumeroa.
He died in hospital two days later.
Rameka did not participate in the attack, but the Crown says she shared a "common intention" with the others.
The Crown says the murder was gang-related, as Mr Kumeroa was wearing red, a colour associated with the Mongrel Mob.
Rameka's group was associated with Black Power, an enemy gang.
Ms Uruamo said she saw Mr Kumeroa walking down the street, and saw a car drive past him and stop.
She described seeing a female with a ponytail yelling out of the car window when the car first pulled up.
"When I close my eyes I think about that girl in the back. I can see a ponytail, fringe, dark. And that's it," she said.
Ms Uruamo struggled to remember certain details.
But she said at some point she saw Mr Kumeroa being pulled out of the back of the car and pushed to the ground.
She saw a female pushing him out of the car and a male pulling him out.
She also heard female voices yelling.
Ms Uruamo heard a female yell "get back in the car," but could not remember when during the attack she heard it.
Her husband, Jamie Uruamo, said he saw a female passenger get out and tell the men "come on, let's go" as the two men tried to drag Mr Kumeroa towards the car, after one of them had hit him on the head with an axe.
Witness Joshua Takarangi recalled hearing a female yell "get the f*** back in the car" in a panicked tone before the weapon had been produced, but after the two attackers had pushed Mr Kumeroa to the ground.
Witness Maciu Torogi saw the female driver, who is known to be Jamie Ahsin, get out of the car and yell for the men to get back in the car before the weapon was produced.
The trial continues, before Justice Rebecca Ellis.