The photographs are now all she has of her daughter, and while she cherishes the opportunity to see her face every day, the pain that once caused her to hide the photos away has never faded.
Although Viki carried her daughter to full term, Tilly was born underweight, underdeveloped and with a range of illnesses commonly associated with premature births.
Chief among these was necrotising enterocolitis (NEC), an inflammation of the bowel that can cause its contents to leak into the abdomen.
NEC is rare in full-term babies. As Andy Cole, chief executive of Bliss, the charity for premature and sick babies, explains: "NEC is a very serious condition which most commonly affects premature babies. However, ten per cent of NEC cases are found in full-term babies. These cases are often associated with an underlying health issue. It is often difficult to diagnose but can usually be successfully treated either medically or with surgery."
Usually, but not always.
It was a cruel turn of fate for Viki, who had already seen her fair share of heartache since she learned she was pregnant in December 2003.
Viki was only 20 when she met the father of her tragically short-lived daughter on an internet chatroom earlier that year.
"I wasn't looking for a relationship," says Viki, who is now 27 and lives in Penicuik. "We were just chatting but one day he asked to meet up. I wasn't too sure but we had been chatting for a good six or seven months, so I agreed and we met on 27 September, 2003. We really hit it off.
"On 17 December that year, I found out I was pregnant. I was absolutely shocked. It obviously wasn't planned. We weren't serious about each other, we were just having fun.
"I texted him – which probably isn't the best way to tell someone they're going to be a dad – but I didn't receive a reply."
Aside from a couple of apologetic texts and a few vague promises over the term of the pregnancy, Viki never heard from the boy again.
Despite the emotional trauma of facing life as a single mother, the pregnancy went off without a hitch until about three weeks before term when she noticed a watery green discharge.
In two separate tests over the next week, nurses dismissed the greeny liquid first as normal pregnancy discharge and then thrush, but after two weeks the discharge still hadn't stopped.
"I finally got to see a doctor on 16 August, 2004 and he told me that I was 3cm dilated and that I was about to go into labour. When the baby was born, there were no waters.
"The midwife was shocked that it was a dry birth, but Tilly was crying so I thought everything was all right."
Everything was far from all right. Despite her full term, Tilly was found to have a gestation age of just 31-34 weeks and an inflammation of the bowel that required an urgent operation.
Despite the doctors' initial hopes that the operation was a success, her condition soon deteriorated.
"A nurse and two doctors came into my room," Viki continues. "They sat me down and said that they had some bad news. One doctor told me that they didn't think Tilly was going to make it. I wasn't prepared for that.
"He asked if I was in contact with Tilly's dad. I still had his mobile number, but it just went through to answer phone.
"I left him a message saying that if he wanted to see his daughter he better hurry because she was dying, but I never received a reply and he didn't make any effort to be there.
"My own midwife came in to see me and I gave her a big cuddle. I wanted my family with me to come and see Tilly before she died, but my brother-in-law only had a two-seater car so the midwife went all the way from Edinburgh Royal Infirmary to the other side of Edinburgh to collect them.
"We took Tilly to be baptised and after that she passed away."
It was a devastating blow for Viki, who had to undergo counselling to come to terms with the loss and still feels aggrieved that the early warning signs she presented in the weeks before weren't picked up by the nurses.
She says: "The cause of death was put down to the hole in her bowel and necrotising enterocolitis. They did a full investigation and found that no-one was at fault, but I'm convinced that the discharge I had for weeks was my waters slowly leaking out.
"I think Tilly must have been inside me for about two weeks without any fluid, which is why she was so small when she was born because she hadn't developed properly.
"We would just like someone to turn around and say 'I'm sorry, we were wrong' but no-one admitted any fault even though I had been telling them something was wrong for weeks.
"The warning signs were there. I just want an apology."
An independent consultant was brought in to review the case and found no evidence of negligence.
The consultant stated: "Tilly had several risk factors associated with the development of NEC in a full-term baby.
"She was of low weight for her gestational age. She had polycythemia (a rare blood disorder], a recognised association of intrauterine growth restriction.
"There was also prolonged rupture of the membranes . . . I am unable to determine from the case notes whether the paediatricians who were at the delivery were aware that there was the possibility that the membranes had ruptured at 38 weeks or indeed that the obstetric and midwifery staff attending Tilly's delivery considered this likely.
"It is my opinion that Tilly's post-natal management was reasonable. The treatment was given expeditiously. I can find no evidence that failure to apply any treatment might have changed the outcome."
Six years on, NHS Lothian maintains that the treatment Tilly received after she was born was reasonable.
Maria Wilson, chief midwife at NHS Lothian, said: "I would like to express our sincere condolences to Miss O'Donnell. It is always difficult to revisit a case six years on, especially when a formal complaint has never been received. We met with Miss O'Donnell and her family at the time to discuss the circumstances in greater detail, but if any issues remain unresolved or Miss O'Donnell has any unanswered questions, we would be happy to meet with her again."
When Viki's sister Kay-Leigh had her own child, a son called Tyler, a few months later, it was a bittersweet moment for Viki.
She says: "When she had her baby I was glad it was a boy, because a girl would have reminded me too much of Tilly. Even then I couldn't go near him without feeling a lot of pain, but I had to push through it because it was important for us to bond."
It was a bond that seemed to transcend death, for Tyler didn't only bond with Viki but also with the late cousin who could have been so close but who he never got to meet.
"Tyler used to ask for Tilly when he learned to speak. He would say, 'Where's Tilly? Why can't I see her?'.
"We saw him sitting on a step one day apparently talking to himself. We asked him who he was talking to and he said, 'I'm talking to Tilly'."
WHAT IS NECROTISING ENTEROCOLITIS?
NECROTISING enterocolitis, or NEC, happens when the tissues in the intestine become inflamed and start to die. This can lead to a hole in the gut developing, allowing the contents of the intestine to leak into the abdomen and cause a serious infection.
According to Great Ormond Street Chidlren's Hospital in London, NEC can be difficult to diagnose although the condition is becoming more common – most likely because more premature babies are surviving.
Just 10 per cent of cases of NEC are found in full-term babies. Symptoms include problems feeding and a swollen and sore abdomen. NEC is the reason for most surgical emergencies in newborn babies. Operations to close the hole and remove the dead tissue take between 30 minutes and four hours. The vast majority of NEC cases are treated successfully with children going on to lead normal lives.
There is no specific support group for parents of babies with NEC but Bliss, the charity for premature and sick babies, may be able to help. Contact the national family support hotline on 0500 618140 or Bliss Scotland, PO Box 29198, Dunfermline, KY12 2BB, 0845 157 0077 or [email protected]