It is a very tough situation , as in one the judgement of Hon`ble Supreme court, it was held that -
In Geeta Satish Gokarna vs Satish Shankarrao Gokarna on 29 March, 2004 in this case the wife agreed, at the time of divorce by mutual consent not to seek maintenance, having receieved an amount as full and final settlement, but afterwards claimed maintenance u/s 25 HMA. The Court held her claim to be maintainable – held – Right to maintenance is a part of larger right to life and any agreement to the contrary is against public policy and pro tanto(to that extent) ineffective.
So, only distress circumstances may only be compelling reason to seek any claim in future.
Also, affidavit in this regard may be - how much money or benefits she received in settlement and she will not apply maintenance in future, and that should part of court record,
Only if she re marries or in relationship with some other person, than you will be absolutely exonerate from any maintenance in future.