She switches constantly between being extremely guarded and tremendously engaging.
Straight-talking and petite, Muirhead's laughter permeates our interview throughout.
After a lifetime in Whitehall - at the MoD and then the Department for Food, the Environment, and Rural Affairs - Muirhead has, since 1 April, had her attention fixed firmly on politics within a community setting.
Describing herself as a 'council crusader', it is ultimately down to her to better the reputation and case for local government. This is a crucial time for the Local Government Association comms team, which is to launch a national five-year campaign next month.
Several major local government communications players have come on board to implement the 'reputation project', as it is called. The aim is to improve radically the image of local government and help the LGA lobby for greater devolved power.
LGA research has revealed the public regards local government as a 'sloth' or an 'ostrich' - slow-moving and prone to sticking its head in the sand.
The LGA is eager to increase the public's satisfaction with local councils and will put communications at the heart of its plans.
Muirhead's life has been an eventful journey, with her focus shifting now from the global to the local. Born in the Scottish Highlands, Muirhead's international upbringing appears to have set the tone of her career.
Her father's job in the oil industry meant she spent her childhood in Iran. She reminisces how safe life was for children and how she would play on the streets around eucalyptus trees with Persian friends, long before the Iranian revolution forced ex-pat communities into compounds for security.
A degree in Russian from Birmingham University led Muirhead to her first job as a translator at the MoD in 1979, a time when all operations were kept firmly from the eyes of the public.
'When I got my first job at the MoD I was told to tell everyone I was a civil servant and that I counted paper clips,' Muirhead chuckles. She rose to become head of comms with a brief to provide transparent communications 'because that's what (then defence secretary) George Robertson wanted'. Indeed, Robertson described her then as the MoD's 'media commander'.
Towards the end her time at the MoD, Muirhead became one of the senior staff invited to attend the Royal College of Defence Studies for its one-year course on defence and security. This took her to Africa to advise on military and diplomatic policy. It provided first-hand acquaintance with African poverty, the memory of which remains.
'The amazing thing is the people's sense of hope and optimism,' she recalls.
'The people were looking into the future despite the appalling things that were going on day in and day out.'
Muirhead says she is driven by being able to make a difference to people's lives. In 1996 the MoD monitored thousands of refugees flooding out of Rwanda into forests in Zaire, from one civil war to another. Aid agencies were unable to reach the refugees in Zaire and the MoD rallied support to move into the country with its NATO allies.
The militia in Zaire listened on local radio as Muirhead broadcast the MoD's plans, and reacted by creating safe corridors to enable the Rwandans to flee back to the border to get aid.
'Through the power of communications we avoided a massive disaster, which was incredible,' she said.
While part of Defra's programme to modernise rural delivery, Muirhead was introduced to the devolution of power to local communities - hence the appeal of the LGA post.
Given the 'head-in-the-sand' image of local government, it is encouraging to hear Muirhead describe herself as 'energetic, fast moving and extrovert'.
If she can start to mould the image of local politics into her persona, the appeal of local democracy should get stronger.
1979: Russian translator, MoD
1985: Policy and operations officer, MoD
1997: Head of comms and chief spokesman, MoD
2001: Policy and operations officer, MoD
2003: Director of modernising rural delivery, Department for the
Environment, Food and Rural Affairs
2005: Director of strategy, Local Government Association