I have already posted on the other AIBU thread.
The NHS is not there for all the world to use for free, other countries charge both its citizens and tourists for health care in the USA if you have no money or insurance you don't get treated.
It is also rather telling that having totally flouted the laws of this country by over staying the parents are trying to use the law to get the operation, I am assuming the law firm they are using is doing the work for free otherwise one would ask why are the parents spending money on lawyers if they cant afford to pay for the treatment.
My own 8 month old DD died as a direct result of NHS cuts when they closed our A&E department and she died because we couldn't get treatment in time.
I am helping raising funds for another UK child to go to the USA for treatment as our NHS wont fund the operation she needs, yet illegal immigrants believe they have the right to have free treatment.
Of course its emotive when its a child, but the situation she is in is due to the parents not getting their immigration status sorted out and they, not UK citizens or the UK health service must bear the responsibility.