Nada left the family home -- an upmarket apartment block on Ash Street in Cambridge, Massachusetts -- at 9.30am, entrusting her baby daughter to Brady McCarthy's care.
Little Rehma slept from 10am to approximately 1.15pm on the afternoon of January 14, prosecutors have said. Now they are trying to piece together the chain of events from 1.15pm to 4.42pm, the time when the nanny made a call to the emergency services.
Prosecutors allege that little Rehma was alone in Brady McCarthy's care up until she dialled 911 at 4.42pm. The police arrived and found Rehma unconscious in her cot but breathing.
She was subsequently rushed to Boston Children's Hospital. Further investigations into her injuries showed that she was suffering from subdural and retinal haemorrhaging and cerebral swelling. She had a broken arm, a broken leg and was bleeding from her brain and eyes.
"There was bruising under the scalp, bruising on the buttocks and compression fractures on the vertebrae that would be consistent with the slamming of a child," according to assistant DA Katherine Folger.
On January 16, Rehma was declared brain-dead and taken off life support. Lawyers acting for the nanny point out that Rehma had been on several family trips to Pakistan, Saudi Arabia and London in the months prior to her death.
They have also claimed that a doctor had diagnosed Rehma as "malnourished".