Millie Thompson started coughing and crying in a high chair during her mashed lunchtime feed from a supervisor at a nursery in Cheadle Hulme, Greater Manchester, before her lips turned blue.
The nursery supervisor -whose basic first aid certificate had expired - shouted for help and passed her on to a colleague who did have paediatric first aid training and proceeded to give her back slaps.
Millie's condition fluctuated and then deteriorated as an ambulance arrived 10 minutes after staff at Ramillies Hall private school dialled 999 on October 23 last year.
There were no signs of life as she was taken to Stepping Hill Hospital and she was pronounced dead soon after arrival.
It emerged during the hearing at Oldham Magistrates' Court that Millie suffered a rare complication as a result of the choking in which air was able to get into her partially blocked airway but not out.
The trapped air placed pressure on her heart, which led to a fatal cardiac arrest.
The jury agreed it was "a difficult to diagnose complication" and that in the circumstances they "did not believe that the outcome for Millie could have been different".
The inquest said Ramillies Hall did fulfil its legal requirements in ensuring at least one staff member with a current paediatric first aid training certificate was on the premises at any given time.