After farewelling her "strength and stay" at the small service, Her Majesty returned to her apartment at Windsor Castle and wanted to be "alone with her own thoughts".
Angela shared the details of the private afternoon in her book The Other Side of the Coin, excerpts of which are appearing in Hello! magazine ahead of its publication next month. She's been the monarch's personal advisor and senior dresser for almost 30 years and is the first member of royal staff to be given permission from the monarch to write a book.
"I helped her off with her coat and hat and no words were spoken," Angela wrote. "The Queen then walked to her sitting room, closed the door behind her, and she was alone with her own thoughts."
Angela shared how members of the household staff came to pay their respects as Philip's coffin made its journey from the castle.
"You could see the expression of sadness on everyone's faces to see such a great and well-respected man making his last journey," she said. "Their thoughts, I'm sure, were for The Queen, knowing she had lost a husband and a best friend. The nation shared the grief and their hearts went out to Her Majesty."
The Queen first met Angela during a visit to Germany, where she worked as a housekeeper for the British Ambassador in Berlin, who was hosting the Monarch's visit.
When Angela returned to the UK the following year, Her Majesty offered her a job as her dresser.
Speaking with The Telegraph in 2007, Angela said, "I suppose the Queen must have liked me and decided I was trustworthy and discreet."
While her official title is personal assistant, adviser, and curator (jewellery, insignias, and wardrobe), she is a trusted confidante and friend.
"We discuss clothes, make-up, jewellery. We say, 'Would this piece of jewellery look nice with that outfit?', and things like that," she told the publication.
She added that their close relationship has caused jealousy among other members of staff, joking, "I don't have any more room for knives in my back."
Never miss a thing. Sign up to Yahoo Lifestyle’s daily newsletter.
Or if you have a story idea, email us at firstname.lastname@example.org.