Will
Is it legal for an attorney to change the word granddaughter to grandson in a Will after the person has died?
Re: Will Change
a Will may only be amended at the instructions of the testator (the person for whom the Will is written) and only then as long as that person is mentally competent. Therefore, once the testator has died, the document becomes "final" and is "set in stone" so to speak.
Your Q raises the issue of whether the drafting attorney make a mistake or misunderstood in the drafting process, and the testator actually intended to leave that property or inheritance to a granddaughter instead of a grandson -- such as if there was only a granddaughter living at the time the Will was written. Even then, the proper "fix" to correct any such drafting error is through a court hearing and order of the court correcting the Will to comply with the testator's true intentions.