Vic lake murder accused still behind bars

A mother-of-seven who denies drowning her three youngest children by driving into a Melbourne lake will remain behind bars ahead of her murder trial.

Akon Guode's bid for bail was refused on Thursday by Magistrate Carolene Gwynn, who said she had not provided sufficient reasons to justify her release.

The 37-year-old has pleaded not guilty to murdering her 1-year-old son, Bol, and twins Hanger and her brother Madit, 4, who drowned when her car plunged into the lake at Wyndham Vale in April 2015.

Guode has also pleaded not guilty to the attempted murder of her 6-year-old daughter, Alual, who survived after being pulled from the water with her mother.

Guode has been committed for trial and is due to front the Victorian Supreme Court for a directions hearing on Friday.

Prosecutors have levelled a series of allegations against Guode, including that she:

* Drove around the Lake Gladman area five times before her car went into the water on April 8;

* Appeared to make deliberate steering moves before her car entered the lake without braking;

* Did not attempt to help her children or assist rescue efforts;

* Was battling financial hardship and rumours within the Sudanese community before the crash in relation to an affair with the children's father.

A key witness, who can't be named for legal reasons, claims she overheard Guode say she would "rather take her own life and that of the kids" than see them live with her lover, Joseph Manyang, and his wife.

The woman also claims Guode believed the "witchcraft" of Mr Manyang's wife might have caused the crash.

Ms Gwynn said the credit of that witness and her statements would need to be considered by a jury.

The court has been told the witness has mental health issues, and was abusing drugs and alcohol at the time of the alleged conversation last year.

Guode, who has no prior history, says she suffered a dizzy spell and ended up in the water.

The court has heard she suffered from headaches that caused dizziness and affected her driving in the year leading up to the incident.

Mr Manyang, who fathered the four children involved in the tragedy, believes it was an accident.