The death of the little girl, named by relatives as Bellah-Rose Salafia, is being treated as suspicious.
Emergency services were called to a “disturbance” at a home on Handford Rd, Zillmere just before 6am on Saturday.
The baby was found unresponsive and was taken to Prince Charles Hospital but died that day.
Results from her autopsy are expected today to confirm the cause of her death.
A homicide investigation has been launched, and a major investigation centre has been set up at Boondall police station.
Police would not confirm if the girl’s parents or carers are involved in the investigation.
“Investigations are ongoing and several people are assisting police with their inquiries,” a Queensland Police Service spokesman said on the weekend.
No arrests had been made by Monday afternoon.
Toys and flowers have since been left outside the home.
“I love you endlessly my sweet niece, my heart is broken and forever will be,” one aunty wrote on social media.
“You are and always will be so loved, my heart aches my angel, rest peacefully our beautiful girl.
“I’ll help look after your mum and your three brothers always and know that you will have justice.”
She said the baby girl’s family “doesn’t even know what happened” and will not know “until the police figure it out”.
Investigators are appealing for anyone who may have dashcam footage from along Handford Rd between 4.30am and 6.30am on Saturday to come forward, contact Policelink on 131 444 or Crime Stoppers on 1800 333 000.