Simmonds had briefly stayed with her mother and asked to be dropped off at a Countdown supermarket in Whangārei.
Today, Callen told the High Court her daughter yelled something at her as she drove away, but she couldn't make it out at the time.
"After about half an hour's driving I was trying to figure out in my head what she yelled at me, and I suddenly clicked: 'Oh my God she said 'don't forget my headstone'."
Samuel Hemuera Pou is on trial in Whangārei, accused of murdering Bridget Simmonds. Photo / File
Callen said her daughter was very sore from a beating on Valentine's Day, when she came to stay.
She said her legs were covered "black and blue" with bruises from her hips to her knees.
Senior Constable Joanne Rouse spoke to Simmonds after this assault. She said one of Simmonds' eyes was weeping and she couldn't open it.
Pou has admitted causing these injuries, at a pre-trial appearance.
Crown Prosecutor Mike Smith read an agreed summary of facts that said Pou tried in the Valentine's Day beating to gouge out Simmonds' eyes and punched her ribs to stop her screaming.
He said she saw a GP the next day.
"It was discovered that her left cornea was ripped and hanging off, the victim had lost vision in her left eye ... the doctor also observed that the victim's face was very swollen and bruised and she had pain in the right side of her ribs."
