Shona Mullen, 59, passed away on March 5 after a long battle with bone marrow cancer myeloma.
Son Scott Mullen, 27, and his wife Aileen, 29, are expecting their first child in July - and Shona is the only one in the family to know the sex of the baby.
In a touching gesture, the couple asked the sonographer who performed the 20-week baby scan to write the gender on a card which was sealed in an envelope.
They then took the message to the St Andrew's Hospice in Airdrie, where Shona was being cared for, and nurse Frances Kelly read the important news about her first grandchild after they left the room.
Shona, who was weak from treatment, managed to nod her approval. She died the next day.
The card and the sonogram picture were placed inside Shona's coffin with her.
Only child Scott, from Motherwell, said: "My mum was delighted for us when we told her Aileen was pregnant but I know she was worried she would never get to meet the baby.
"We didn't want to know the sex but we wanted her to know.
"So the sonographer who performed the scan at Wishaw General turned the screen away to see and wrote it alongside a message for my mum.
"When we got back to the hospice, a nurse read the card to her.
"She asked if she was happy with the news and she nodded her head.
"My mum died hours later."
Now Scott, supported by his closest friends, will attempt to give something back to the people who showed his mum such care and compassion in her final days.
And when he sets off to climb Ben Nevis on June 28, Shona's voice will be clear in his head.
The last time he attempted the challenge he found it so tough he thought about giving up before reaching the top. He called Shona to tell her he was struggling and it was her encouraging words that pushed him to the summit.
Scott, a sports production journalist at the Evening Times, said: "I was close to my mum. She is the reason I love sport. As a wee boy she would take me to Motherwell matches, at home and away."
As he grew up, Scott remained close to his mum and the family was rocked when Shona, who led an active and full life, was diagnosed with myeloma in February 2009 after repeated visits to her doctor with backache.
Scott said: "I was just 22 at the time and I remember feeling like my whole world had imploded.
"We were told the cancer was treatable but it wasn't curable."
Over the next five years Shona underwent round after round of gruelling chemotherapy.
But the cancer-free periods in between each treatment grew shorter.
SHE also underwent potentially life threatening stem cell treatment, when she was implanted with her own bone marrow and quarantined for three weeks.
This took place in June 2012 around about the same time the couple got engaged.
Scott and Aileen wasted no time planning their special day, conscious of the fact Shona's health was failing.
The wedding was held on August 2 at Oran Mor in Glasgow's West End.
Scott said: "My mum was ecstatic about the wedding and became involved with the planning. She would say 'It is your decision....but I would do it this way'.
"My mum loved the day and afterwards she showed all the pictures around to her friends and nurses and doctors.
"They became like her friends which is nice but also sad because it shows how often she was in hospital."
In October last year Shona fell seriously ill after a particularly strong round of chemotherapy treatment.
In the months that followed her condition deteriorated and she was cared for by Scott's gran Jessie Boyd, 86, before a space was found for her at St Andrew's Hospice, where she stayed for five days before passing away.
Scott said: "When my mum was sick we all felt really helpless. But fundraising is a way for me to take control and do something positive.
"Several of my closest friends will join me in the climb to the summit on Saturday, June 28, so that other families can have the comfort that this wonderful hospice provides."
Scott has already raised nearly £1500 for the hospice, which needs £65,000 per week to provide vital care for terminally ill people in Lanarkshire.
A spokeswoman for the St Andrew's Hospice said: "We provide specialist care to approximately 120 patients each week.
WE also offer a range of support services to the patients and their families to help them with the traumas and challenges they face.
"To enable us to continue to provide these vital care services free to our patients, we have to raise £65,000 each week.
"I would like to thank Scott for thinking to help us by climbing UK's highest mountain to raise much- needed funds for patient care.
"We all have the ability to make a difference to people's lives and making a donation today will help us care for the patients who may need us tomorrow. Because you care, we can care."
Sponsor Scott by visiting http://www.justgiving.com/climbforshona
The family, including Scott's aunt Sandra Blair, cousin Emma Tod and his gran Jessie, have thanked all those who cared for Shona, in particular Frances Kelly at St Andrew's Hospice, staff at the medical day unit at Wishaw General Hospital and consultant Dr Charlotte Thomas.