She went into hospital for a routine scan, but the result was anything but routine - doctors found an intracardiac mass filling most of the left chamber of baby Carsen's heart.
Mrs Coll was airlifted to Starship Hospital in Auckland, where the cardiology team worked hard to diagnose the problem.
But the news was bleak - specialists told her that if Carsen wasn't stillborn, he would live for only a short period of time.
"The prognosis for Carsen was very poor," Mrs Coll said.
Remarkably, Carsen survived childbirth, but the first scan of his heart the next day revealed the extent of the tumour. Doctors said it was inoperable and there wasn't anything they could do.
What they couldn't predict, however, was that Carsen was a fighter.
"Carsen has defied all of the odds, really," Mrs Coll said.
"He pretty much has a plan of his own -- he's not done anything that anybody expected. He's quite a remarkable baby to be honest."
Carsen continued to grow and thrive, despite the tumour.
"Eventually they sent us back to Christchurch with a 'watch and wait' approach."
For a number of weeks, Carsen's tumour appeared to be static, but a later scan showed it was growing at the same rate as his heart.
Now Starship's cardiac surgeons are planning an operation unlike any other. Specialists don't know exactly they are dealing with -- there are a few possibilities what the tumour might be, but they can't say for sure.
"None of the team have ever seen anything like it."
What is certain is that the procedure will be a very risky and complicated. It will take place at the most vital part of the organ, near to where the heart's rhythm is regulated.
"It's actually a very critical place, where the operation is taking place, and not somewhere that they would normally, generally operate."
Mrs Coll said people expected her to be very upset or in a dark place - but the reality was the opposite.
"I look at Carsen every day and I think that he is a typical example of someone who is defying the odds," she said.
"I have absolutely every belief that he will tackle this in the same way that he's tackled all of the other challenges, so we're right behind him.
"It is a hard time for the family and the people around us, but we're strong and we have good support, and we believe in Carsen."
The family received some high-profile support today from Newstalk ZB's Mike Hosking, who featured the Colls on his ASB Good As Gold segment.
Hosking told an emotional Mrs Coll that ASB would contribute $2500 towards the family's costs. He also offered Oli and Carsen $500 in Toy World vouchers.
Friends of the family have also rallied around the Colls. They have set up a Givealittle page which has so far raised almost $7000.
