Maida Vale grandmother Phyllis Earl died in December last year after tripping over while charging her electric car.

The 77-year-old fractured her hip while charging her beloved G-Wiz on Randolph Avenue and died in hospital after complications during surgery.

Mrs Earl was born in New York on December 21, 1932, and was brought up in a town outside the city called Purchase.

After her father died when she was 15, the family moved back into the city and she studied at Rosemary Hall boarding school – now known as Choate Rosemary Hall – whose alumni includes John F Kennedy and Michael Douglas.

She graduated from Vassar College in 1954 and, following a year at the Sorbonne in Paris, found a job in public relations in New York.

In 1958 she was recommended to Grace Kelly, who had married Prince Albert of Monaco and was looking for an American personal assistant who spoke French.

She spent four years working for Princess Grace in Monaco, during which she lived some of the time in the Royal Palace and built up a close friendship with the family.

In 1962 she married Julian Earl, a merchant banker based in London whose great-uncle was William Somerset Maugham and grandfather the Viscount Maugham, who was Lord Chancellor in the late 1930s.

The couple moved to London where they had three children, Cordelia, Sebastian and Austin. In the early 1970s, Mrs Earl set up a property business called Helping Hands – now called Proprium – with a close friend and worked for the company until retiring in 1993.

When her husband died in 1990, Mrs Earl moved to her Randolph Avenue flat where “she was very good friends with all the neighbours”.

In her later life she spent much time volunteering as a lay visitor, ensuring the humane treatment of prisoners at local police stations and gave many hours reviewing Westminster Council CCTV film for the same purpose.

She also took courses at the Westminster Adult Education Service and spent 10 years volunteering for the Survival International charity, campaigning for tribal people’s rights.

Her daughter Cordelia Uys said: “She was completely amazing.

“My boys adored her and she was involved in every aspect of their lives.

“She went to watch all their sports matches, took them to exhibitions, helped with their birthday parties and picked them up from school.

“And she absolutely adored my twin nieces. She wasn’t a person who ever made a fuss about anything.”

She leaves behind her three children and five grandchildren Theo, Fabian, Maxim, Yuna and Mio.