I answered her question by stating the following:
The first question I would ask myself in your circumstance is, do you know if your grandmother kept any important documents in a safety deposit box or a safe. The second question, I would ask myself is, do you know if your grandmother had a family attorney. Generally, will documents are kept in a safe place by the decedent or with someone the decedent entrusted. Your son’s grandmother should have informed you where she generally kept her important documents. If the whereabouts of the will or trust document is unknown to you, I would be also digging around the son’s grandmother’s house and/or trying to find if your son’s grandmother had a family attorney.
If all that fails, then I would begin looking for one of the two witnesses who were present at the signing of the testator’s will. If you are able to find just one of the witnesses, then you may be able to prove the contents of a will, but this must be done before a court of law. That very witness may be able to tell you what was left in your grandmother’s will.