The woman was charged yesterday with three counts of maliciously administering poison with intent to harm.
Magistrate Dermot Kehoe today ordered she remain in custody, saying she posed an unacceptable risk to herself and her children, prompting the defendant's mother to break down in tears in the courtroom.
Solicitor Jason Buckland told Southport Magistrates Court that department officers had visited the 25-year-old woman's property only four hours before her three daughters were admitted to Gold Coast Hospital on Thursday night suffering stomach aches, headaches and drowsiness.
The department and police had been aware that the woman, who cannot be named, had threatened to kill herself and the children - aged three, six and nine - only a fortnight ago.
Prosecutor Christina Heffner told the court that on January 24 the woman had made a threat to police, stating: "All children will be taking many sleeping tablets and we'll all go to sleep for a very long time."
The department and police intervened, and the threat was not carried out on that occasion.
"I've asked for a full account of what contact the Child Safety Department has had with this mother and the reasoning behind any decisions that have been made," Ms Boyle said.
The most important thing was that the children were safe in foster care, she added.
Just before 8pm AEST, the woman had forced her children to swallow the valium tablets, despite the oldest daughter spitting them out because they "weren't very nice".
In a police interview, "the suspect made a full admission to causing her three children to ingest approximately 10 tablets of diazepam (valium)," Ms Heffner said.
Police allege that 10 minutes later the children became "unsteady on their feet and drowsy".
"In fact the youngest one started to fall asleep and could not be woken," Ms Heffner said.
Child Protection Unit detectives interviewed only the eldest daughter in hospital the next morning because her siblings were "too groggy".
"She explained that her mother was in an intoxicated state and she was told she had to take sleeping tablets so that everything would be better," Ms Heffner told the court.
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