Let's eliminate the red herring about Ms Kelly's son and his special needs.
Of course, many children with special needs are educated in the "private sector", since many special schools are not part of the state system.
Provision for residential education for children on the autistic spectrum, children with sensory impairments and children with profound physical impairments tends to be in schools managed by national charities, but with their pupils' costs met by the local authorities. In only a formal sense are such children educated in the "private sector".
That is not what Ms Kelly has done. She has purchased a place at a fee-paying special educational resource from which pupils often progress to traditional private schools.
Her actions, however, remind us that Labour was supportive of comprehensive education and hostile to selective and private education. It is worth recounting why the bulk of Labour Party members and supporters once took such a view.
Comprehensive education sought to ensure that no child was pigeon-holed into failure by an exam at the age of 11. It sought to eliminate the freemasonry of the old school tie, the jobs-by-connections culture. That system entrenched the privileges of the already successful, and it held back enterprise and initiative.
All children have strengths and weaknesses, but the weaknesses should not preclude the child from further developing his or her strengths. The capacity for all children to learn was anathema to those shackled to a social perspective which saw "the rich man at his castle, the poor man at his gate".
In a healthy society, young people of all backgrounds mix freely and not solely with those from the same background. In so doing, they develop the skills which will create a democratic and tolerant world. Selective, and particularly fee-paying, schools militate against this - perhaps the very reason some support it.
Of course, comprehensive education had failures as well as successes.
Pedagogic babies were ditched with the selective bathwater. The system requires - deserves even - a continuous evaluation. All of these "Labour"
arguments for comprehensive education, however, were under-pinned by two other, traditional social democratic values: first, that the market was not a good means of regulating society; second, that a more equal society was a desirable thing.
English New Labour has abandoned its commitment to these values as well as to comprehensive schooling. The Kelly issue is only an indicator of that.
It would be useful if the commitment of the Scottish parties to either the comprehensive system or the market system of schooling was a key part of the debate as we approach the May elections.
Alex Wood is headteacher of Wester Hailes Education Centre, Edinburgh