Thank you for your question
My name is Clare
I shall do my best to help you but I need some further information first
Was there actually a Consent Order or not?
So there was a financial settlement via the courts?
Did you have legal advice at the time?
So the order was then made by Consent?
Which child is ill?
How much is the house worth and how much is outstanding on the mortgage
How much does a two bedroom property in the same general area cost to buy?
But you will not be in the same position in 15 years time
I am afraid that since the Order was made by Consent it cannot be appealed except in very specific circumstances - none of which apply here
The fact that your son may need more care MAY be a reason to make an application for more provision BUT this is not something that you can deal with now as there is no way of assessing now what the needs of your son will be then
You will need to review this in five years time and consider the needs of your son then and at that point you might be able to make an applictaion using the Children Act.
Please ask if you need further details
In Barder v Barder  2 FLR 480, Lord Brandon set out that a court may grant leave to appeal out of time on the ground of new events if four conditions are satisfied:
Please note I am afraid that your sons recent diagnosis will not be sufficient