Hannah collapsed in the chemist and the pharmacist gave her an an EpiPen injection in her leg, the inquest heard.
Attempts to resuscitate her were started and a customer called an ambulance. Paramedics soon arrived and continued resuscitation efforts.
Hannah was taken to hospital where she was declared dead by 13:00 GMT, according to her family’s lawyers.
She said her daughter had followed a policy of complete avoidance of milk, eggs, wheat and fish, never ate at a friend’s house and would only eat at “known and trusted” restaurants.
Ms Duyile paid tribute to her Hannah’s selfless nature, saying she would clean house without asking and looked after her sister.
“She was allergic to eggs but put on latex gloves to cook some for me at my birthday as a surprise,” she said.
She said her daughter “had a strong sense of right and wrong, if she thought something was unfair she would speak her mind no matter what”.
“She would have made a great lawyer,” she added.
