The X-ray revealed the everyday item Mila had swallowed.
All it took was Emily Neilan turning her back for 60 seconds on her then 10-month-old daughter Mila for their lives to change dramatically.
The 25-year-old first-time mum from Sydney was folding clothes on her bed on January 5 with her curious toddler, who had recently become fascinated with opening cupboards, in the room with her.
Unbeknown to Neilan, Mila managed to chew through the packaging of a four-pack of button batteries, swallowing one of the 20mm discs in the seconds she had her back turned.
"After she had swallowed it she put the packet back in the drawer, closed the drawer and has gone on about her morning, watching The Wiggles," Neilan told news.com.au.
Afterwards Neilan noticed Mila seemed off and a "bit tired", refusing her bottle – but she put it down to her daughter just being at a fussy age.
Neilan settled her down for her morning nap and gave Mila to her sister-in-law to babysit so she could go to a meeting with photographers for her upcoming wedding to fiance Dane Toohey, which was scheduled for February 29.
When the meeting ended two hours later and Neilan saw Mila, she knew immediately something was wrong.
Not only had Mila not woken up from her nap but she was "like a ragdoll" and had "no reflexes" when they did try and rouse her.
"When she brought her into me she was very, very lethargic. She had almost no reflexes in her arms and legs, she had almost become like a ragdoll, so her eyes were open but in terms of her limbs I couldn't put her down and sit her up on her own," Neilan said.
"She wasn't pulling herself up on couches. I just immediately went into a bit of a panic and said to Dane, 'We've got to get in the car. We've got to go to the ER'."
Neilan and Toohey rushed their daughter to The Children's Hospital in Westmead, Sydney, where doctors immediately began trying to work out what was wrong with Mila.
"I'm thinking to myself, has she bumped her head?" Neilan said.
"I'm going through all the scenarios in my head – has she fallen over? Has she hit her head on something that's caused a neurological issue? Honestly I had no idea what had gone on."
Doctors decided to send Mila for an X-ray and within five minutes Neilan was called in to take a look at what they had found.
There "clear as day" was a 20mm disc – a button battery – lodged in Mila's throat.
"Once we had worked out it was a battery I called my sister-in-law and said, 'Hey can you go into our room and can you go into our bedside table and tell me is there a packet of batteries in there with one missing?'" Neilan said.
"And she sent me a photo of the packet and there was one missing."
Mila was then rushed into surgery where doctors managed to remove the battery.
But they had to install a gastronomy button, as the damage to her oesophagus meant she couldn't ingest food or liquids orally.
Mila spent the next fortnight in the intensive care unit before doctors performed a second surgery as the damage from the battery had caused her windpipe and oesophagus to join together.
During the 12-hour surgery, skin grafts were taken from Mila's neck and behind her ear to seal the inside of her oesophagus.
The major surgery required Mila to be intubated and put in a coma for 12 days afterwards as she had constant lung collapses and her heart even stopped for nine seconds as she recovered from the surgery.
But today, Neilan said that it would be hard to know Mila had been through such a difficult time.
While Mila will need more check-ups and care in the future, the now 15-month-old has made a remarkable recovery.
"You look at her today and you wouldn't even know that she has been through something so traumatic," Neilan said.
Mila's time in hospital meant that the couple had to cancel their wedding and Neilan has described the whole experience as the "most traumatic event in my life".
But she is incredibly grateful to the hard work of staff at The Children's Hospital for keeping Mila alive.
"I just had my second Mother's Day and it was so emotional for me, because I may not have been able to celebrate Mother's Day the way that we did," she said.
Neilan encouraged other parents to be vigilant around batteries, especially those in packaging which claimed to be childproof.