AN over-protective mother didn't toilet train her children because she couldn't bear to see them grow up, a court has been told.

She kept her son in nappies until well past his fifth birthday, The Daily Telegraph reported.

A Family Court of Australia judge found that if the two children were to live with their mother they would have no relationship with their father.

This would expose them to emotional harm because of her inability to let them become independent and develop like normal children.

The father, who has been given custody, told the court he believed the mother had not toilet trained the children, aged five and almost four, because she could not bear to have them grow up.

He told the court the older child would not even feed himself, insisting that he be hand-fed.

The mother claimed the children only wore nappies when they were leaving the house.

But Justice Garry Watts said he did not believe the children had been toilet trained in the conventional sense and he believed the older child was deliberately not going to the toilet for psychological reasons.

A interim order earlier this year saw the children go to live with the father after the mother sent him a letter stating it was "all gonna end very soon".

In a judgment published this week, Justice Watts handed the father sole parental responsibility, giving the mother only supervised time with her children until next February.

The parents have been ordered to ensure the children are fully toilet trained.

Justice Watts said if the children lived with their mother they would be exposed to her irrational ideas and fears.

He said he accepted a doctor's opinion that the mother's "enmeshed relationship" with the children was likely to undermine their psychological needs and could have drastic consequences.

"(The doctor) considers the mother to be extremely overprotective and is finding it difficult to let the children separate from her and assert their independence," Justice Watts said.

The mother wanted the older child home schooled.

In February, Justice Watts ordered that the boy attend school immediately, but in his latest judgment he said that was yet to occur.

The mother made a range of allegations against the father in court, but Justice Watts said she did not impress him as a reliable witness.

At times, he said, she appeared to be fabricating evidence.

The father claimed she would stop at nothing to avoid him having unsupervised time with the children.