Jennifer Crichton, 34, of Slater Lane, Leyland, denies murdering seven month old Amelia Crichton at their home last April.
It is alleged she left her with "catastrophic" head injuries, including bleeding on the brain, in her right eye and a fractured skull - but she told police Amelia had collpased after letting out "an almighty scream".
In the 12 minute 999 call she made at 12.19am on April 19, she is heard to sob: "She just woke up and started being sick."
The defendant had been receiving help under a court care order to look after the child at her home.
An hour and 20 minutes after her support worker left, she rang 999 for an ambulance reporting her daughter was not breathing.
Before the audio was played Christopher Tehrani QC, prosecuting, said: " Jurors may find the content distressing at times because they will hear CPR being administered by Jennifer Crichton to Amelia and hear at times Jennifer Crichton 's distress."
Crichton, wearing a pale blue hoodie, hung her head down in the dock and wiped her tears with a tissue as the call was played.
She was heard to tell the ambulance operator: "She's only seven months old.
"She's laying on the floor.
"She was really premature - she was born at 23 weeks."
Crichton is heard crying as she is told to stay calm and how to administer CPR.
She says: " The foster carers just left. She's under a care order.
"Because she's under child protection I've got somebody in til 11pm."
Two days later doctors concluded Amelia would not recover from her "catastrophic" brain injuries and further life support was withdrawn at 8.15pm on April 21.
She was declared dead 20 minutes later.
Crichton was arrested four days after her daughter's death.
The baby's dad, Richard Shephard, from Ribbleton, is expected to give evidence on Friday.