Can a signature be revoked?

[johnnymous]

Jurisdiction

United Kingdom

A friend of mine has recently signed a document relinquishing her right to part of an inheritance. She was not aware that this was the purpose of the document she was signing. This friend had been a trustee of her stepfather and mothers will and has now inadvertantly written herself and her sisters out of a part of the estate. Is there anything that could be done challenge this?

 

[army judge]

We discuss the laws of the US federal government, the US states and her territories.

No one here knows anything about the laws of your island nation.
I suggest you seek the counsel of a solicitor.