Today is McGrath's first day in the job at Westpac but she has had plenty of experience coping with the challenges of banking and Covid after coming from a role managing the branch network, call centres and digital arm for Barclays bank in the UK.
"That was a particularly amazing but tough challenge during 2020 because the UK government required bank branches to be open all the way through.
"To persuade people to leave their homes and go and support customers when all the signage that you were seeing was stay at home to save lives taught me a huge amount about leading people through a crisis but also supporting customers in a real time of need."
After spending eight years in the UK McGrath, who was born in Wellington and grew up in the Bay of Plenty, says it was Covid that made her realise what was important and brought her back home.
"I was used to coming home quite often, 2020 was a bit of a shock to the system and really helped focus the mind on what was most important - and that was family.
McGrath start her new job based in Wellington but plans to move to Auckland once the border has been removed and two-way travel is possible.
Already she has zeroed in a desire to improve Westpac's relationship with its customers.
"If you look at customer results in terms of net promoter score it would say we have got some more to do.
"I want to build on the great legacy that I have inherited and then help get that customer advocacy further up the list."
Last year a Westpac investor discussion pack revealed it had the lowest net promoter score of the major banks at 14. ANZ, ASB, BNZ and Kiwibank had NPS of 28, 32, 39 and 42.
McGrath said her big focus for the first few weeks would be a catch-up with all the bank's stakeholders by talking to staff, customers and its regulators.
"I've got a lot of listening to do and asking questions. I think having done that process I will have a clearer idea about what I think the priorities are over the next couple of months."
Outside of Covid, Westpac New Zealand has had a tumultuous last year.
Its parent ASX-listed Westpac Banking Corporation weighed up whether to sell or float the New Zealand business on the sharemarket before deciding to hold onto it.
It has also had a number of run-ins with the regulator.
In August the Reserve Bank issued a formal warning to Westpac for failing to comply with anti-money laundering rules.
Earlier this year it ordered Westpac to commission two independent reports to address concerns around the bank's risk governance processes.
Asked if there was anything in particular she planned to clean up at Westpac, McGrath said it was too early to know but she hoped to have a frank discussion with the regulator.
"I think sometimes when there is a new person in you can have - you get that one chance for them to have a very frank conversation because you haven't been here before.
"I really want to have that conversation with the regulators and with the teams and particularly from a customer perspective too because getting that brutal truth about here are the things we are awesome at and here are things that you really need to focus on and do more about and quite quickly - I think that is a fascinating perspective to get from that group of stakeholders."
McGrath said one thing her experience of working in London through Covid had taught her was to be ready for change.
"I learnt that you had to be pretty agile with your plans because they were forever changing in the UK in terms of what you were allowed to do."
Rather than work from home during the pandemic, she based herself out of the Clapham Junction branch, allowing her to see exactly what her staff were facing on a day-to-day basis.
"From a leadership perspective, the thing I learnt the most was about to speak a bit more with my own voice which was partly because I could write about the experiences that I was having in the branch that resonated with the team of 16,000 that I had but could also write about how weird it was."
She remembers thinking how crazy it was that both herself and her two siblings in New Zealand were having to deal with a large crisis and high stress levels despite being based on opposite sides of the world.
"I remember sitting there and going this is just bonkers."
But McGrath said the challenges of last year meant everybody learned quite a bit about themselves.
"Talking to friends in Auckland they are going through a lot of the same emotions and challenges that I did last year in London. You certainly find out a lot about yourself when you are put in unusual circumstances, which we definitely are at the moment."
