Now she faces an agonising wait to see if she will be granted a student visa, which will allow her re-entry.
"I'm really sad because all I want to do is dance, I just wanted to get started at my new school.
"I landed and went through border control and told them that I was going into the country as a student, they looked over my paperwork and then took me to one side.
"I was taken to an interview room where they searched me and my bags. Someone took my fingerprints and pictures. After a few hours they told me that I wouldn't be allowed in to the country.
"I was tired and I felt a lot of panic and stress. I just started crying and crying and I was scared.
"When they tried to explain to me why I had to go home I was in a state of shock so it wasn't until I'd had some time to think that I understood what had happened."
The Epsom Girls' Grammar School student flew to London last year to audition for a place at the competitive London Russian Ballet School.
After the audition she was invited to stay on for six weeks to allow teachers to assess her talent in various dance disciplines, her academic potential and overall attitude.
I just started crying and crying and I was scared.
To her delight, Ms Kushnir was offered a full scholarship to the private school, which charges students $12,255 for a full term.
"I was so happy when I got accepted. They have some of the best teachers in the world," she said.
"I've been dancing since I was a little girl, it's all I want to do with my life. My goal is to get a job with a dance company and travel the world.
"I like the feeling I get while dancing, I know it sounds cheesy but I feel free and it's the best feeling in the world."
The family moved to New Zealand 13 years ago and Ms Kushnir attends dance ballet lessons at Mt Eden Ballet Academy. Her school and dance teachers are supportive of her future.
Ms Kushnir's mother Natasha, spent more than $2000 on return flights and revealed her frustration at the decision to not allow her daughter into England to start her studies.
"My daughter was treated like a criminal, had her fingerprints taken and was allowed to call a friend in London who then contacted us in New Zealand," said Mrs Kushnir.
"It isn't easy because you don't know who to call, where she is, and when we did finally get hold of someone we were told that the decision had been made and was final.
"She was so happy when she was accepted and she got this email from the school to tell her that she can come as a tourist, while they took care of the student visa.
"She had a return flight, enough money to look after herself and had accommodation arranged which is what it said on the paperwork," said Mrs Kushnir.
The London Russian Ballet School offers a three-year, sixth form vocational course in the Professional Russian Ballet Method, which students must attend six days a week.
At the end of the course, students receive a Diploma in Professional Russian Ballet Training, A-level certificates in chosen subjects and full assistance with UCAS applications for university.
The school believes each student must be a rounded individual prepared for life beyond school in an increasingly competitive world, so academic work is compulsory.
According to the United Kingdom Government website, you do not need a visa to study for 6 months or less if you have a New Zealand passport.
However, it states that you should bring documents with you to show at the border. The gov.uk website then directs you to the relevant student visa guide to see what documents to bring.
