Cancellation of gift deed

One of my client has executed a gift deed in 2013 giving some share in property to her Husband and 2 sons equally.

Now she want to cancel the part of gift i.e. gift in favour of one son.

Her Son is ready to sign the cancellation deed. Now question is Whethere the deed of cancellation terminating the part of the gift deed or cancelling the gift given to one of the son out of all donee can be executed or not.

Thanks