• Ayzlee McCarthy, of Iowa, spent the day after Christmas playing with her dress-up clothes and a doll of the snowman Olaf from the movie ‘Frozen’
• Then she began complaining to mother Amber that her legs hurt so much, she couldn’t walk
• In less than 72 hours, she would be dead at Blank Children’s Hospital in Des Moines
• Her family is still struggling to understand how a vaccinated and otherwise-healthy child could die from the flu so quickly 

By MailOnline Reporter

Published: 21:47 GMT, 3 January 2015 | Updated: 15:03 GMT, 4 January 2015

An Iowa family was left shocked and confused after their three-year-old daughter died from the flu not even three days after she fell ill.

Ayzlee McCarthy, of Elk Horn, spent December 26 running around the house with her siblings and playing with her Christmas gifts: dress-up clothes and a doll of the snowman Olaf from the Disney movie ‘Frozen.’

A day later, her legs ached so badly, she couldn’t walk. 

Then on December 28, Ayzlee was rushed to a hospital in Des Moines and hooked up to an IV. 

She died the following morning, just 13 days after her third birthday, of influenza A and B with sepsis, The Des Moines Register reported.

Her distraught mother, Amber McCarthy, is struggling to understand.

‘She was healthy, she had a flu shot — the whole thing is so unreal,’ Amber McCarthy told the Des Moines Register.

‘This shouldn’t be happening in 2015,’ the mother added. 

Ayzlee was an active child, known for her infectious excitement and love of singing popular tunes like ‘Let It Go’ from ‘Frozen.’ 

She was proud of having recently completed potty training.

Her parents say Ayzlee had spent the day after Christmas running around the house with her siblings. Nothing seemed amiss.

McCarthy took her daughter to a nearby clinic when she began complaining that her legs ached badly. 

The mother, a respiratory therapist, at first thought she could have a urinary tract infection. 

‘She tested positive for both [influenza] A and B,’ McCarthy told the Register. ‘I never in a million years thought that was what we’d be at the clinic for.’

McCarthy took her daughter home made sure she drank plenty of fluids and gave her ibuprofen.

Ayzlee seemed to be feeling better on December 27. She watched cartoons while her mom cooked for her.

‘I made her some toast, and she told me what a good ‘cooker’ I was,’ McCarthy told the Register.

But later in the day, something changed.

‘She sat there looking through me and not at me,’ the mother told the Register. ‘I knew something was not right.’

McCarthy took her to a nearby hospital, where Ayzlee was hooked up to an IV and seemed to not recognize her mother. She was eventually transferred to Blank Children’s Hospital in Des Moines, but her condition continued to worsen.

‘She kept saying how tired she was,’ McCarthy, who spent the night lying with Ayzlee in her hospital bed, told the Register.

Then about 4am on December 29, woke up to her daughter’s labored breathing and racing heart.

‘Mommy, I so tired,’ Ayzlee said. ‘I done.’

McCarthy told her daughter she loved her as nurses intubated her. Her heart stopped beating as the mother watched the procedure from the hallway. 

‘They tried three times to bring her back,’ McCarthy told the Register. ’I said, “Keep doing it.”‘

By the time McCarthy’s husband Jim arrived, Ayzzlee still had a weak heart rate. The parents went in and told their little girl they loved her one last time.

She died minutes later.