Despite her unassuming and gentle nature, Fiona Castle, widow of children's television presenter Roy Castle, is more than forthright when it comes to talking about how, after years of loneliness and depression, she turned to God and became a Christian at the age of 35.
Roy's death on September 2, 1994, could have plunged Fiona back into depression, but instead, sustained by her faith and love, she has faced the future with her four now grown-up children.
And, in addition to touring to spread the word about her unshakeable belief in God, and campaigning the world over against the effects of smoking, she has continued the great work her husband undertook before his death, aged just 62, in raising awareness and money to combat lung cancer.
She has frequently been a visitor to schools where her talks on the more than 400 chemicals used in cigarettes and the effects of passive smoking and death of her husband have been soberly received.
The visit to Londonderry came about following an invitation from Rev Pat Storey.
Fiona began her short 'tour' with a talk at the White Horse Hotel on Thursday evening, and on Friday night she spoke to members of the Mothers' Union, Church of Ireland and guests at Jackson's in Ballybofey.
"That's how we met - as a result of just having a chat one day, when Pat just said would I like to come over and speak at some meeting that she would set up.
" I became a Christian about 30-something years ago now and I just share my story about how I became a Christian because I went through depression.
"It's really just a story to encourage others that there is a different way of life if you want it, to make the most of the moment and not to live with regrets, take up challenges," she said.
The former classically trained dancer, continued: "I was married to Roy when I was 23, had four children and I was really quite lonely in a way because I was mostly on my own because Roy was away travelling, working abroad and so on, so I found the weight of responsibility weighed heavily on me and I got quite depressed.
"It seemed to get worse and worse and whatever I tried to do to make life work didn't seem to work. I always felt a failure and I used to look around and see other people doing really well and coping and I didn't have anything really to complain about - I had a fantastic situation - enough money, nice home, healthy children - everything that one would say would make life happy.
"But I wasn't happy and one day in utter desperation I got down on my knees and said 'If you are out there do something'.
"Almost immediately a Christian woman phoned me saying she had me on her mind and had this sudden urge to ring me and felt I needed to talk and would I like to have coffee with her.
"I decided this was a good answer to prayer so I went around and talked to her and she just led me to Jesus and my life just turned around from that moment onwards, and I just realised that I didn't have to worry about what other people thought of me - you know, I just had such low self-esteem and I was always trying to match up to what I thought other people expected of me.
"I was always trying to be the person I thought other people wanted me to be and suddenly I was able to just let go of all that and just be me. I just had peace from that moment onwards," she said.
Now she is the author of eight books, has had a regular daily slot on London's Premier Radio, and her work with the Council of the Evangelical Alliance has seen her take on an extensive speaking ministry throughout the country.
A previous visitor to Coleraine, where she was the guest speaker at a New Horizons event, this was the first time that Fiona ventured over to the Maiden City and she admitted to being smitten by the "beautiful" landscape that surrounds the city in between her official visits that have also included meeting Bishop Ken Good and his wife, Mary.