I've just listened to the interview, and she didn't say 'hair' at all. What she said didn't even sound like 'air'.
What she said was:
'When I was doing my A-levels I was modelling a lot, so...'
A levels (pronounced Ay- levels) are exams taken in UK schools at the age of 17/18.
And, by the way, she doesn't have a Devon accent. Not everyone in Britain has the accent of the region where they happen to have been born. Like most educated young people in Britain, she has a fairly neutral non-regional accent.