The body of her alleged victim, who is yet to be identified, was discovered in the Maribyrnong River at Flemington on Sunday.
A 49-year-old West Footscray woman was arrested on Tuesday afternoon, alongside a 15-year-old boy.
She was charged after being interviewed by police, and the boy was released without charge.
Police alleged the accused woman knew the victim.
She faced Melbourne Magistrates Court on Wednesday afternoon, where her lawyer applied to close the court to media and members of the public.
A magistrate later told media he would suppress the woman's name, but did not inform reporters of reasons for the suppression as they were heard in closed court.
"I'm not going to discuss those matters," Magistrate Stephen Ballek said.
The woman's lawyer said her client suffered from nerve damage to her lower back, for which she received steroid injections.
She said the 49-year-old had been diagnosed with depression and anxiety, and needed to be seen by a forensic nurse as she is currently medicated with Lexapro and Valium.
The woman did not apply for bail.
The magistrate asked the accused woman to stand as he remanded her in custody to face court again on July 23 via video link.
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