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Thank you for your question
My name is Clare
I shall do my best to help you but I need some further information first
What is the exact wording of the Order for sale?
Who is paying the mortgage?
Is there any reason why you do not simply return the matter to court?
Whether or not you can charge "occupational rent" depends on the wording of the Order.
However there is no reason why you should not put her on notice that you intend to do so - although the fact that she is paying the mortgage makes it unlikely that a Court would order it.
I hope that this is of assistance - please ask if you need further details