It wasn't really a bone of contention in our house, so different to your circumstances, but we moved county when I was 14. Even though it was to a nicer school and a nicer town, it wrecked my self-confidence (which wasn't great before hand) and took me till university to really come out of my shell.
It's individual to every family but from my own experience, I wouldn't move our DSs at that age.
Would you still want to move to Devon later on, when she's late teens / university?
our 12 yr old daughter had problems settling in to high school as she is very shy,also had problems with some bullying she begged to move schools,we had put the house on the market as we had been thinking about it for a while and decided to move to Devon, however several months down the line,the bully has left and our dd is now happy in school ,is doing well academically and has been chosen to represent her year in a media group and won the spelling bee.After viewing house in devon and going to see potential new school she became extremly upset about moving schools i am very very concerned that we are doing the wrong thing as i think to have dd happy and settled in school is priceless,there are rows every day and not a nice atomosphere in house i think we should postpone the move as i am worried she may never get her confidence back as it has taken her a year to feel settled my OH thinks we should still move i am caught in the middle,any thoughts ?