"I just thought I was a normal person, going to school," she says. "I didn't think anything of it. But the other pupils did."
At primary, some pupils would ask her what her head felt like and want to touch it. Others teased her and called her "baldy".
When, eventually, she fought back, she immediately got into trouble for fighting.
Her secondary school experience, at Queen Eleanor technology college in Stamford, Lincolnshire, has been more positive. Teachers have made an effort to learn about her condition and allow her to wear a hat during lessons.
As her classmates grow older, they have become more supportive. But Emily finds the girls' increasing preoccupation with hair difficult.
Equally, she finds it hard when occasionally people make unthinking reference to hair loss. Once her science teacher, complimented on his hair by a pupil, said: "I don't think I could cope without hair."
And, twice, supply teachers have asked Emily to remove her hat.
However, she has always had a teacher to talk to when she is upset.
"I had a bad patch at the end of last year," she says. "But whenever I've had a hard time, I could talk to my tutor-mentor or my head of year.
They've given me advice and basically helped me through.
"Now, if anyone says anything, I think it's their problem, not mine.
"But it makes it so much easier if someone cares and will listen to what you think."
* Emily has set up an online support group for young people with alopecia: www.chipsunite.org.uk
Photograph: Steve Hill