The short answer is maybe. In order to create or change a Will your grandmother needed "testamentary capacity." This requires that when she signed the Will she:
Understood the nature of the business in which she was engaged;
Comprehended generally the nature and extent of the property which constituted hed estate;
Held in her mind the names and identity of those who have natural claims on her bounty; and
Appreciated her relation to the members of her family.
Even if she had some mental difficulties, if she had a "lucid interval" and could satisfy the above criteria, then amendment to the Will would be legally valid.
That being said, if there were concerns about that, you can always challenge the Will. Time may be of the essence as you only have 3 months from the date a Will is probated to challenge it. See Section 2107.76 of the Ohio Revised Code (link below)
https://codes.ohio.gov/ohio-revised-code/section-2107.76
Answered on Oct 15th, 2021 at 10:02 AM