I am so sorry for your loss.  While I can see that you may think that notarizing the signature may indeed be an issue, really the notary is only affirming that the person that signed the document is in fact who they say that they are.  Now, you have not given any details about whose signature the notary notarized.  If the notary is an attorney and an executor in some states the courts will frown on that in the first place.  Most Wills do not have to be notarized (that is the signature of the decedent).  What are notarized are self-proving affidavits of witnesses.  I can see an issue also if the executor/notary is also the beneficiary under the Will.  Have some one take a look at it as a whole.  It is worth asking the question.  Good luck.