Went with our three year old who had very long hair. Asked for a couple of inches, hairdresser took over double that to the extent it is so short we can now no longer tie all her hair up (not great for bath time or nursery). I was standing in front of her to encourage her to look down and so was unable to see how much was being taken off.
Was also very impatient and unsympathetic when my daughter started getting bored. AVOID AT ALL COSTS!!!