Married on Sunday, pregnant on Wednesday, a widow on Friday.

That was the heartbreaking, bittersweet reality which confronted Hobart woman Meredith Wilson seven years ago.

Sandy Duncanson had lived with cancer for 16 years, the last four in a relationship with Meredith.

Throughout his 20s and while studying law, he endured multiple operations, chemotherapy and radiotherapy.

Despite the challenges, Sandy completed his degree and became principal solicitor at the Tasmanian Tenants Union, just one of the roles he relished in advocating for social justice.

Fast forward to 2017 and his legacy continues through a bursary, a lecture series and, more poignantly, two daughters he has never met.

Meredith met Sandy during a period of good health through a shared love of mountain bike riding.

"In the beginning, I think I had a bit of an abstract idea about it [his cancer] because he was so healthy and full of life," she said.

"About six weeks into our relationship, he had a health check in Melbourne and was told that the cancer was back."

It was a watershed moment in their short lives together.

During a phone call, he metaphorically opened the door for her to leave, but she didn't.

"He said 'If you want to stay with me, come to Melbourne and be in the appointments and understand what's going on with my health and what we can expect the impact to be on both of our lives'," Meredith said.

"He was unwell for a lot of our relationship, so it was enormously stressful."

Beaming groom defied the pain

The couple was determined to live their lives to the full, as much as the bouts of illness allowed, and even began planning for children.

"He talked to me about the possibility that he mightn't be there to help me raise our family but the thing about Sandy is, he was such an optimist," she said.

"I don't think he really ever properly confronted that he might die ahead of his time.

"I think in the back of his mind he knew it, but he didn't want to believe it, so he kept on living his life like it wasn't going to happen."

Just months before Sandy's death, the couple decided to get married.

The couple were married just days before Sandy's death. ( Supplied )

"He wanted us to celebrate our marriage with all the people that we loved and that were important to him," Meredith said.

"He found it very difficult and painful to get in his clothes. He was on the oxygen in the car as we pulled up to the house. He was determined not to walk in with the oxygen and he did that.

"He looked gorgeous in his kilt and he stood really tall, and for a man that wasn't very well he was beaming. He was so brave. He was extraordinary."

Days after the wedding, it was time to say goodbye

Before their vows in a South Hobart garden, the couple used the occasion to make a statement acknowledging that many others could not do the same.

"That was very important to us," Meredith said.

"We have a lot of friends who are gay, who are in loving relationships, and we felt that we couldn't possibly not acknowledge their relationships because we love and respect them, and feel that they should have a right to be married and acknowledge their love for each other in that way."

But within days of the wedding, Meredith was preparing to say goodbye to Sandy.

"The last days, I still find hard to think about because he was unconscious and uncomfortable," she said.

"We had decided to care for him at home because he was too young a man to die in a hospice."

Luka and Iris' family include their father in family celebrations. ( ABC News: Gregor Salmon )

The gift of new life amid the grief

The success of a scheduled IVF procedure that stressful week was the furthest thing from Meredith's mind.

But 10 days after Sandy passed away, she discovered she was pregnant.

"I felt like I had been gifted this little part of Sandy. It had been the most extraordinary couple of weeks with the wedding, and Sandy passing and then finding out I was pregnant, I really thought I was floating, or I was dreaming," she said.

"It was extraordinary, it was the furthest thing from my mind because we had been going through IVF for three years.

"Iris was six of eight embryos. At that point I wasn't expecting to be pregnant at all.

"I felt my heart singing; I felt so incredibly happy about it.

"[It] completely changed my grieving process because I felt like I had this baby I had to care for and look after for the future.

"I felt I could not lose myself in being overwhelmed or really sinking into the grief because I had that very positive thing happening."

Luka and Iris will get to know about their father's work through the university bursary. ( ABC News: Gregor Salmon )

'I try to make him present in our lives'

Meredith's decision to have a second child stemmed in part from her desire to give Iris a baby sister or brother.

"I wanted her to have a sibling, to have someone who would always be there for her so that they would be together. If anything happened to me that they'd have each other," she said.

With two embryos left, Meredith returned for another round of IVF.

She fell ill after the seventh embryo was implanted and it failed, but the final one was strong — Luka.

Meredith talked to the girls about their father from the beginning.

"I wanted it to be a very gradual and gentle thing, so I do try to make him very present in our lives," she said.

"We visit his grave and celebrate his birthdays, and always bring his presence into our Christmas celebrations.

"I want him to keep being present in their lives, and I want them to know him and know what an extraordinary man he was.

"He was very brave and adventurous and determined ... just full of fun, very mischievous with a naughty sense of humour."

Luka was born when sister Iris was two years old. ( ABC News: Gregor Salmon )

A way for the girls to know their father

Sandy is also very present in their lives through a bursary set up at the University of Tasmania in his honour.

Family and friends rallied after his death to establish the Sandy Duncanson Social Justice Fund.

Launched by Justice Michael Kirby in 2011, it has grown from plans for a one-off bursary into now awarding two bursaries a year to students demonstrating a commitment to social justice.

"When Sandy died people were a bit at a loss at what to do, where to put their grief and energy.

"[The bursary] was a beautiful coming together of Sandy's friends and supporters of his values."

The ongoing bursary and lectures are also a way for the girls to learn more about the father they would never meet.

"The lecture and the bursary is about Sandy's work and his values and I think that tells that story really well," Meredith said.

"There's been a lot of energy and goodwill from family and the committee and all the donors, and that is really a testament of Sandy's strength and character and how his work inspired people.

"It feels like a powerful thing. I think he would be enormously proud of it."

The seventh Sandy Duncanson Foundation lecture will be delivered by gay rights activist Rodney Croome in Hobart on Thursday night.