Chidinma Anya, 45, was accused of driving erratically at about 50mph in a 30mph zone when she crashed into a van.
Her daughter Eugenie Anigbo was tragically killed in the crash on Kings Highway, south London. The van driver Dean Snow was also badly hurt.
Anya was told she there was a high chance she would be sent to prison when she is sentenced.
During a hearing at the Old Bailey, Anya, from Thamesmead, south London, pleaded guilty to causing Eugenie’s death by dangerous driving and causing serious injury to Mr Snow.
For the defence Tarquin McCalla told the court Anya had a “history of seizures”, which was a feature of the case.
He also said she was the sole carer of her three remaining children, now aged four, seven and eight.
He warned Anya: “You do not need me to tell you how serious this is.
“It could not be more serious for you, I recognise that. But you must be prepared on November 9 for a custodial sentence.”
Ms Anya who is on unconditional bail, nodded and replied: “I lost my baby.”
She will be sentenced on 9 November once pre sentence reports are gathered.