They took all her valuables including her cell phone and the shoes she was wearing, Ms Wang said.
Father Sam Wang, 52, a housekeeper, said he did not recognise her when he found her after the attack.
"We got worried when she didn't come home and I couldn't reach her on her mobile, which was switched off," he said in Mandarin.
"I took a drive out to look for her and found her lying on the ground in the car park.
"Her face was bruised, swollen and covered in blood. I could not recognise her."
Mr Wang said the attack had terrified his daughter, and she was now receiving counselling.
He said the family had lived in New Zealand for 12 years and had always thought of Auckland as safe.
"I am really shocked that something like that can happen to someone taking public transport," Mr Wang said.
The woman's mother was in tears when she spoke to the Herald.
"I just want the culprits caught and I hope people with information will contact the police," she said.
"I hope this will also make others realise that it is not safe travelling on Auckland trains, and they must take extra care."
Yesterday, a police officer was seen talking to Ms Wang at the hospital.
A police spokeswoman said they weren't notified of the attack until long after it happened, but would be investigating.
She said a further update would be made available once the investigation was complete.
