But only ten days after she underwent the lumpectomy in October 2016, an emergency MRI revealed the cancer had spread to her spine.
She said: “It hit us like a tsunami when we found out it was in my back as well.
“When we first found out and we were told that it was primary breast cancer we thought we’d won a watch because my back had been so sore for about 15 months. We were delighted because at the back of my mind there had been a niggle that they could be linked.”
Due to her health, Liz had to take early retirement from Police Scotland where she had served for three decades, climbing up the ranks to superintendent.
She said: “I knew as soon as I became ill there was no way I could work because of the treatment. I miss the job. I loved being a police officer. It was my life for 29 years. It’s a 24/7 job and it’s not as if you ever walk away from it.”
Now Liz, 53, is looking forward to making her catwalk debut for Breast Cancer Care Scotland’s annual charity fashion show at the end of the month.
Liz’s six-year-old son Liam will be in the audience and it is down to him that she has agreed to take part.
She said: “Being told by a doctor you have tumours up and down your spine is awful. I was trying to get myself physically fit because my son was only four at the time and I wanted to look after him.
“I can’t lift him and I can’t get down on the floor. He knows mummy can’t do those things and that’s why the fashion show is so important to me because it’s something I can do that’s very different to what he sees me do.”
Liz, who attended a Breast Cancer Care Scotland support group, turned down the modelling opportunity at first.
She said: “My immediate reaction was no because it was so different. Police work is not glamorous but then I thought, no, I can do this.”
Liz and partner Di, who celebrated their civil partnership on the banks of the River Tay in 2010, talk openly with Liam about her cancer and it is their tight family unit that gives her strength.
She said: “I can’t bear the thought of not being with him when he’s growing up but that makes me fight to try and stay healthy and strong to be here for when he’s older.”
Liz, from Edinburgh, manages her pain with a small pump device implanted into her abdomen that administers medication through a catheter into her spine. She was in the Marie Curie Hospice for ten weeks shortly after her diagnosis due to the agony of tumours pressing on the nerves in her sacrum.
She has undergone radiotherapy and endures bone-strengthening injections every four weeks to help fight the stage four cancer.
She said: “Liam is a great distractor so I don’t really think about it when I am with him but at the same time it is always there because it limits me physically.”
In 2014 in her role as police superintendent, Liz led the search for missing three-year-old Mikaeel Kular whose body was found dumped in a suitcase in woods in Kirkcaldy. His mother, Rosdeep Adekoya, later admitted she had killed him.
Liz, who joined Lothian and Borders Police in 1988, said: “That was one of the hardest cases because of the circumstances and Liam was just a year younger than him.
“I was doing all the media and it was very poignant that I was standing talking about this wee boy who was missing.
“One of the journalists asked me how could a three-year-old open a big metal door and I said well, as a mother of a boy who is a similar age, it’s incredible what they can do when they want to.
“Everybody relates to it when there’s a child involved and it certainly resonated with me more because of my son.”
Liz has had “massive support” from family, friends and former colleagues, but it’s her partner who has been “a tower of strength”. She said: “Even in our darkest times she’s just been amazing.”
Even though doctors haven’t given Liz a firm prognosis, she remains resolute.
She said: “Although it’s a life-limiting illness it’s not what you would call terminal because it is treatable and manageable.
“Nobody knows how long I’ll be able to keep it under control but I’ve managed for the last two years.
“The fashion show has really helped and put me on a real high. I’m excited.”