"As the defendant crossed the street she threw a small bag of potatoes and a can of dog food," Mr Butler said.
Frater was about 4m away from the victim, but missed. She screamed abusive threats at the victim, before entering a nearby service station and locking herself in the bathroom.
Frater refused to come out of the bathroom when police arrived.
After about 10 minutes, she opened the door and was "immediately combative and abusive towards police officers", Mr Butler said.
Frater resisted arrest and kicked at police while they tried to subdue her. She refused to walk outside and had to be carried to the patrol car.
While police tried to get Frater into the car, she stomped on an officer's foot twice and spat in his face.
She pleaded guilty in court to assaulting police, resisting police, shoplifting, and common assault.
Defence lawyer Raukawa Simon said Frater was "very apologetic" and had written a letter of apology explaining her personal circumstances. Frater had just had her child come back into her care, Ms Simon said.
"What a terrible example she's set for her 14-year-old daughter, that's all I can say," Judge David Cameron said.
He labelled Frater's behaviour "disgraceful" and remanded her to April 6 for sentence.