If you did not know her story, you might think she had overdone it at the gym or was recovering from a car accident.
The truth is far more startling. In 2003, aged 15, Emma had a stroke which has left her with continuing double vision in one eye and a weak right hand and leg.
Until her stroke, life was good for the Year 11 East Otago High School pupil. She was fit and healthy.
For several years she had lived with her parents, Robbie and Jackie Bruce, in a 52-room building once part of the old Cherry Farm psychiatric hospital complex, before the family's move to Waikouaiti.
She liked horses, played the clarinet for a time and enjoyed hanging out with her friends.
She had just finished a game of tennis at school one October afternoon and was in the changing rooms when her world fell apart.
''I knew something was wrong. I was trying to talk but nothing was coming out ...
"One of my friends kept saying 'are you OK' but I couldn't answer. There was no pain. I felt faint so I sat down, and then I just collapsed.''
Emma does not remember much about the rest of that day but her friends and teachers took her to the school sick bay, where an ambulance was called and her parents were alerted.
And she remembers the words of the ambulance officer on the journey to Dunedin Hospital.
''He told me 'don't fall asleep, don't fall asleep' but I couldn't stay awake. It was really, really tiring.''
Within days Emma had open heart surgery to remove an atrial myxoma - a non-cancerous tumour which had been growing undetected in her heart tissue.
Emma's medical notes say hers was 3.5cm by 4.7cm - about the size of a matchbox.
If heart tumours go untreated, bits of them can break off and enter the brain via the bloodstream causing a stroke, and that is what happened to Emma.
She still finds it difficult to comprehend.
''I remember a doctor drawing a picture of my heart on a piece of paper and telling me a piece flicked off it and went to my brain. But I didn't know what a stroke was.''
After weeks in hospital Emma was transferred to the Isis rehabilitation unit at Wakari Hospital.
It was frightening, she said.
She was one of only two young people there - the other was a boy with a broken neck - and she couldn't talk properly.
''I wouldn't talk to people. I was too embarrassed to try. I would write notes, but other people couldn't understand my writing.
"It was very frustrating. I had heaps of support from family and all my ... friends came to visit, but I felt like I was all alone.''
Doctors and therapists cleared her to return to school at the beginning of 2004.
By then her mobility, dexterity, speech, typing skills, and comprehension were considered virtually normal, and as long as she did not get overtired, she was expected to cope.
But Emma did not cope.
She was right-handed; that had to change.
Speech was difficult for years and it is still affected when she gets tired.
Her short-term memory was unreliable.
She had dreams of being a vet but eventually dropped out of school in Year 13, when schoolwork and exams became too much.
Already a shy teenager, her confidence dropped to zero.
Her re-emergence into the world was slow.
She completed a computer course at Otago Polytechnic designed for the disabled and said passing that gave her a huge confidence boost.
Then, in 2007, she met her husband, Joe Petch, through a mutual friend. He was a dairy farm worker living on the West Coast.
Emma said they were able to chat via computer at first, which she found easier than talking in person.
Friendship blossomed into love.
They married in Invercargill in 2009 and now have two preschoolers, Skye and Rylie.
Emma said her anxiety was high while she was pregnant with Skye.
''I knew what had happened to me was a freak thing, but I kept worrying she would have a stroke, too.
''Everything was OK, though. And by the time I had Rylie, I wasn't worried about it at all.''
Emma said she was coping well with her busy life now.
She can drive a vehicle - a ''spinner'' on the steering wheel enables her to drive using only one hand - and is successfully running a household and looking after two active youngsters.
She is mixing in the community and is equipment supervisor at Skye's playcentre.
As the years have passed she has found it easier to talk about her experience, and wants to share it more widely to let people to know teenagers as well as older people have strokes, and that strokes are survivable.
''I try not to let what's happened to me stop me from doing what I want to do. I try and get on with life.''
Strokes
• A stroke happens when a blockage such as a clot blocks the blood flow to the brain, or when a burst blood vessel bleeds into the brain. Every day about 24 New Zealanders have a stroke. About six occur in people under 65.
• About 40 strokes a year are suffered by children.
• Different parts of the brain control a person's movements, senses, emotions and intellectual functions. The effects of stroke depend on which part of the brain is damaged and how severe the damage is.
• Strokes are the third largest killer in New Zealand; about 2500 people annually. About 10% of those who die are under 65.
• There are an estimated 60,000 stroke survivors in New Zealand. Many are disabled and need significant daily support.
• High blood pressure is a major cause of strokes. Other contributing factors are obesity, high cholesterol, lack of exercise, smoking, and atrial fibrillation (a type of heart defect).
Source: Stroke Foundation of New Zealand
