East London Coroners' Court was informed on Friday that there had been a "failure of communication" between the girl's mother and the employees of the Costa in Barking, east London.

On February 8, 2022, Hannah Jacobs, who had suffered from severe allergies to dairy, fish, and eggs since she was a toddler, passed only a few hours after sipping the cow's milk-containing beverage.

The coroner also noted that on the day of her death, "neither Hannah or her mother were carrying an epi-pen that had been prescribed" for when she was exposed to an allergen.

A post-mortem examination found Hannah died of a hypersensitive anaphylactic reaction triggered by an ingredient in her hot chocolate that caused an allergic response.

In a statement after the inquest, Hannah's mother Abimbola Duyile said she was "extremely diligent" with her allergies and her daughter took them "very seriously".

She described her as "vivacious, caring, affectionate, energetic, and outspoken... with a strong sense of right and wrong".

"My beautiful Hannah only had 13 years on this Earth when she should have had many, many more," she said.

Ms Duyile said that allergy training "is not taken seriously enough" and that treating it as a "tick box exercise is not acceptable".

The inquest heard that at the time of Hannah's death, allergen training for new Costa staff involved a series of online modules that could be accessed remotely and repeated until answers were correct.

Costa Coffee said in a statement: "The loss of Hannah is a tragedy, and our heartfelt thoughts remain with her family and friends.

"Understanding how this awful situation occurred is in the interest of everyone. We have listened to everything the coroner has said this week and will carefully consider her comments together with any report she may issue and respond appropriately."

Despite her mother having ordered two hot chocolates with soy milk, the teenager had a "immediate reaction" to the beverage, according to the inquest.

Ms. Duyile reported to the hearing that Hannah complained of itching, swollen lips and mouth as well as chest pains immediately after consuming the hot chocolate.

Hannah's mother asked Urmi Akter, who worked in her kitchen, "Can you wash the jug because my daughter has a dairy allergy?" Akter testified in court.

According to Costa's allergen guidelines, Ms. Duyile was not given access to a book with dietary restrictions, the court heard.

In her statement, Ms Akter said she did not show Ms Duyile the book "as she told me washing the jug was fine".

Hannah tasted the drink on the way to the dentist, where she started to feel unwell, prompting nurses to offer Ms Duyile an epi-pen with 300mg of adrenaline, dentist Iqra Farhad told the court.

Ms Farhad said this could have saved Hannah's life, but Ms Duyile decided to go to the chemist for an antihistamine called Cetirizine instead.

She told the court she only saw Hannah briefly and said "there was no sign of panicking or distress".

But when they arrived at the chemist there were no epi-pens due to general shortages, pharmacist Santokh Kahlon said in evidence.

He would "definitely" have used the extra epi-pen from the dentist if he had known there was one, he told the court.

Zeenat Panirwala, a customer in the chemist at the time, added Ms Duyile was "struggling" to come to terms with what was happening as she saw Hannah in distress.

She said she heard Ms Duyile blaming Costa for giving her child the drink and was "hysterical saying 'she's dead, she's dead'".

"The failure to follow the processes in place to discuss allergies combined with a failure of communication between the mother and the barista is the root cause of this death," assistant coroner Dr. Shirley Radcliffe stated.