* Truss navigates week like no other
* Quickly changed gear from energy speech
* 'Billions' speech for Queen Elizabeth
By Elizabeth Piper and Michael Holden
LONDON, Sept 13 (Reuters) - Just a week after Queen Elizabeth asked Liz Truss to form a government, Britain's new prime minister is attending services of reflection across the country with King Charles, determined to strike the right tone in her first days in power.
It has been a week like no other for the prime minister.
Her first big announcement, on only her second full day in office, had been a more than 100 billion pound package to ease the pain of spiralling energy prices. But while sitting in parliament after unveiling it, a much more dramatic statement was brought to her attention - the queen was gravely ill.
Hours later, Truss delivered a statement from outside her new Downing Street office and residence, paying tribute to the queen, who had died at her home in Scotland, plunging the country into a period of mourning.
"Queen Elizabeth II was the rock on which modern Britain was built," Truss said then.
"She has been a personal inspiration to me and to many Britons. Her devotion to duty is an example to us all. Earlier this week, at 96, she remained determined to carry out her duties as she appointed me as her 15th prime minister."
The queen's appointment of her was the monarch's last public act.
With her energy package all but on hold, although households will get the help provided from Oct. 1, Truss instead has had to help guide the nation in mourning while allowing Buckingham Palace to take the lead in its long-planned ceremonies.
So far, several lawmakers and royal observers said, so good.
"I think that she has done very well. She has come over as measured, calm and competent. She has caught the mood of the nation exactly. I am really very impressed," said David Jones, a Conservative lawmaker and former minister.
"I am afraid the energy stuff was completely lost in the noise."
Truss, 47, had repeatedly said during weeks of a contest to become leader of the governing Conservative Party, she was ready to govern from day one to tackle the most daunting set of challenges for an incoming leader in post-War history.
From an energy crisis, to a forecast long recession and the Conservatives behind in the opinion polls, Truss, who was appointed prime minister by the party rather than the country, and her team had barely set foot in Downing Street before they were choreographing her first big statement on fuel prices.