Well IMO this is just another case of the way we obsessively stick to the letter of the lawin this country. Of course education is important and of course we should be teaching our children to respect schools rules, but taking your child away in term time once, maybe twice, in their entire school career does no harm whatsoever either to their education or their respect for rules.
If we are going to fine why aren't we chasing up every day of truancy rather than wait until it's regular? Why isn't the EWO at the houses of parents whose children are late for school 90% of the time, the same parents who are never there at 3.15 but instead choose to saunter up at 3.25 or later each day? I'm a teacher BTW and I day this every day.
Incidently, IME it is always the parents who do have concern and respect for their children's education that are the ones who ask for LOA. Those who don't give a fig just call their children in sick!
Also, as at least one poster has mentioned, some parents are unable in their line of work to take time off in school hols. Should we just say those children can never go on holiday as a family?
To the OP, she had not given consent because it is SATs week and it will affect her stats though only the optionals so don't see the problem. Phone and ask why, see if she'll change her mind. I would think it very petty for a HT or LEA to instigate a fine for a parents with an otherwise good attendance rate.