The defendants deny negligence and counter-claim for damage to the ambulance.
They say Ms Nevin was travelling at excessive speed and did not keep a proper lookout for their vehicle which they say had its flashing blue lights and siren on.
She denies she was speeding and says there were no sirens or lights on.
Ms Justice Mary Irvine is expected to give her decision on the case later today.
The court heard the ambulance was transporting human eye tissue (corneas) from Dublin Airport to St James's Hospital when the accident happened as Ms Nevin was on her way to do some Christmas shopping.
Ms Nevin, who is expecting a third child shortly, told the court her injuries included a broken knee-cap, a broken wrist, and a fractured sternum. She was six weeks in a wrist cast and leg splint and also required surgery. She is also claiming damages for post-traumatic stress.
She denied, under cross-examination from David Nolan, for the defendants, that she was speeding and said she proceeded with caution through the junction. She agreed she had not looked to her left when coming up to the junction.
A motorist travelling behind Ms Nevin told the court he did not hear or see any siren or lights on the ambulance while another motorist gave evidence that he saw only its blue light was flashing, but did not hear a siren.
The ambulance driver, Gerard Grant, said he had switched on both the siren and the flashing lights on the day. He said he had proceeded with caution through the junction and a car had moved out of his way to let him through just before Ms Nevin's car collided with the ambulance.
He denied he had simply "sailed on into the junction" into the path of Ms Nevin's car.