Thank you for your question
My name is Clare
I shall do my best to help you but I need some further information first
Why did you continue to pay twice as much as you needed to?
Why did you not force an earlier sale of the property?
Who paid for the extension?
My apologies for the delay.
The news is not good I am afraid.
You have no legal basis to ask for an extra percentage share - so unless she agrees then all you can claim for is the extra payments that you have made over and above the £79.50 a month that was ordered by the court.
I fully understand why you did not press for the sale at any point in the last four years - but legally you could have done so and the court makes no allowance for your wish to be generous.
I am sorry not to have better news for you but please ask if you need further details