Legal Question in Wills and Trusts in Illinois

You are not obligated to sign this, but if you do not have any basis to question the will then it will make the administration of your grandmother's estate slightly easier for those involved. It was up to your grandmother, provided she was competent when she prepared the will and was not unduly influenced, to dispose of her estate as she chose. If you do not have any intent to contest the will, then signing will just simplify the administration and distribution to those entitled to it, perhaps also saving the estate some expense. If you are uneasy or have more questions, then you should meet with an attorney.