A preschool teacher tried to force-feed children and taped over one child's mouth with tape, former colleagues say.
Lynn Abraham, 59, has denied 11 charges of assault against nine children, ranging from babies through to four year olds.
These include force-feeding children, smacking them, washing a child's mouth out with soap and taping a child's mouth shut.
The first crown witness, Jennifer Wong, described seeing the accused force feed children by holding them down, forcing a teaspoon in their mouth and then holding their jaw shut.
She also said Ms Abraham taped over the mouth of one child with sellotape.
But the lawyer for the defence, Graeme Newell, challenged the witnesses veracity during cross examination.
He said in her original evidence to the police, Ms Wong had said she heard Ms Abraham say she would do "something" to the child, and "a short time later" saw tape on the child's mouth.
An upset Ms Wong replied that it was true that she saw it.
"I can show you how she put the sellotape. You can bring the sellotape, I can show you. I can swear on my daughter's life that she did put it," Ms Wong said.
Ms Abraham said she had also seen the accused feed the child its own vomit.
"It was disgusting," Ms Wong said.
Mr Newell disputed this, saying it was just food that had been spat out, and that she had not mentioned vomit in her evidence prior to this.
The second witness, Santosh Vermula, another former colleague, said the accused told her she had washed a boy's mouth out with soap after he had sworn at a teacher.
"I was shocked, I didn't expect that she would wash his mouth with soap."
Ms Vermula said she had seen the accused smack the hands of children loud enough to be heard in a noisy classroom.
Under cross-examination, she was asked if she had ever heard of the expression 'wash your mouth out with soap', and she replied that she had not.
Another witness, Ines Miranda, told the court that the smacking became more frequent between 2014 and 2016, as the accused became more stressed.
"I'm an intuitive person and I can feel when someone is stressed - she [the accused] had no control of herself," Ms Miranda said.
When questioned why she had never raised the smacking as an issue, Ms Ines said that she was an unqualified teacher as Ms Abraham was the supervisor, she felt she must know what she was doing.
The owner of the child care centre has been given name suppression because the case could cause undue hardship.
The trial is set down for five days in front of a jury of 6 men and 5 women, with Judge June Jelas presiding.