If she has not taken cheque and in a near future if she does not take cheque, then she will not be boound to the terms of the agreement.
Now with the intervention of eleders, try to reach to settlement instead of relying the old settlement. Try to find out the reasons for the estrangement. Without reason, in this world, nothing happens. There must be a reason (s) (whether legal or illegal, rational or irrational, justifiable or unjustifiable) for her behaviour. Once we find out that reason, according to that either compromise for living together or mutual consent for divorce, can be chalked out and during that period you have to take certain steps to keep her in good humour, so that she will not take any steps under domestic violence Act or Indian Penal Code.
By the way, is she a working lady?