My client's mother had executed a Will deed titled as IRREVOCABLE WILL DEED bequething her property to her husband with a condition to enjoy the property during his life time with a condition not to alienate in any manner and after his demise her son to inherit the said property., and also undertook that she will not revoke the Will Deed during her life time. I seek the expert's advice whether that Irrevocable Will Deed can be revoked by my client's mother during her life time?