While she has been an undoubted hit overseas, however, her problems at home now demand her urgent attention. Her Government has now entered a critical phase. The fascination with novelty has gone; the readiness to excuse newcomers to government for occasional lapses due to inexperience has been exhausted; the ability to blame the government's predecessors for inherited failures cannot retain credibility forever.
The time has come, in other words, to deliver not only on the promises made but also on the promise shown. The Government's opponents will want to check that promises have been kept; their supporters will hope to see the promise shown - their potential for good - realised. It is on these issues that the Government will now be judged.
What we saw of the Prime Minister in the Northern Hemisphere suggests that she has it in her to meet these challenges and there are many who will expect the same leadership and far-sightedness, the same readiness to grapple with difficult issues, to be displayed at home as well as overseas.
Part of her difficulty in meeting those expectations is that the bar for reforming governments has been set so high. The great Labour governments of the past have been transformative; they have introduced changes which have shaped and benefited our society over generations. They have shown how powerful a government with imagination and courage can be in setting us on a new and fulfilling course.
The current Government may not quite recognise that they will be judged according to the expectations of their supporters as well as by the hostility of their opponents.
It is their ability to overcome problems that are hardly recognised as such by their opponents - problems such as the element of racism which remains endemic in our society, the growing inequality between different sectors of society in terms of respect and influence and not just financial resources, the narrow base of our economy which limits our economic prospects and leads us to be too tolerant of the damage done to our environment by the demands of primary industry - that will determine how well the Government is perceived to have done.
The successful management of the day-to-day (and inevitable) problems of government matters of course; but real success in terms of transforming our society will demand the vision, courage and leadership she showed in Davos. I think she can do it.