She started having a coughing fit at her GP surgery, choked on her vomit and her panic stricken parents watched as her lips turned blue. She was given oxygen and then rushed across London, sirens blaring.
The doctors diagnosed her with whooping cough (pertussis), an infection of the lining of the airways, which can be fatal in babies. Cases of the illness have risen 147% in the last year, from 421 in 2010 to 1040 in 2011.
Thankfully Emily has made a full recovery but only after two weeks in hospital attached to drips and oxygen. Her parents have been taught CPR to pump her tiny heart should a similar incident occur.
"It was without doubt the most frightening moment of my whole life," recalls mum Louisa.
"She can have a coughing fit at any time - the sound of your child fighting for breath is heartbreaking. Emily was only old enough for the first round of immunisations so she wasn't protected."
Whooping cough forms part of recommended childhood vaccinations. Of course no one can be sure if she got it from an unvaccinated child but what I fail to understand is why any parent would choose not to give their children immunisations against potentially fatal illnesses?
Thankfully most people do immunise their children - latest UK figures show 94.8% of newborn children have their first whooping cough vaccine within 12 months of birth, and by the age of five, 87.7% had been given their boosters, too.
But that means there are still 12 percent of five year olds who are not fully protected.
While I understand parents should be able to decide for their children, by choosing not to they are possibly allowing the virus to spread to babies like Emily, too young to be immunised. Children like Emily who nearly died because of the decisions possibly taken by families completely unrelated to her.
This is a view backed up by many GPs. "Immunisation not only protects your child, but the population, too. When the number of children being vaccinated drops, the number of cases of the illness will increase," explains Dr Sarah Wigmore.
And surely for every parent the risk of your child contracting a deadly disease outweighs other side effects?
Sarah, 37, from North London does not agree and says she will never immunise her two children.
"I feel there is not enough research on the long term side effects of mass vaccination, plus the likelihood of illness is so small, " she explains. "Ultimately I do what I think is right for my children and I'm not ashamed to say that."
Even so, surely for Sarah's children, the likelihood of illness is so small because the rest of us have vaccinated.
And then there are those parents who change their mind about vaccinations at a later date.
"Initially I thought it was unnecessary to assault my baby son's immune system as a newborn," explains Jess, 36, a stay-at-home mum from Bristol.
"I had read that vaccines could make him more susceptible to asthma, colds, eczema, ear infections and other common illnesses. Also, I was breastfeeding and he was not in nursery so I thought the chances of him contracting these diseases were very rare. I was friends with many women who made the conscious decision not to vaccinate, some of whom had medical training, so I decided it was safe," she explains.
But as her son got older and started mixing with others she changed her mind, deciding that her son was robust enough to cope with vaccinations, and eventually started the immunisation programme when he was three years old in spite of her husband still having doubts.
"Without doubt I began to worry that my son might get ill and I could have prevented it. Plus I was scared he might pass on that illness to someone else and I couldn't live with that."
And Jess is right; imagine living with the pain of knowing that your decision had killed another child. A non immunised child of eight years old may be fine if they catch whooping cough. They may just need to visit their GP, but what about the health of a newborn baby like Emily who is waiting in the GP surgery at the same time.
I'm all for freedom of choice but at what cost?
What do you think?
Is it your social responsibility to have your child immunised or up to parents to decide when and if they want to have a child vaccinated?
Click here for a vaccination check list and timings.