Legal Question in Wills and Trusts in Pennsylvania

After your mother's death, NOBODY can change the will except as by a family settlement agreement (which sometimes occurs for various reasons) between the executor and all of the beneficiaries.

However, you indicate that you are the beneficiary of an IRA. IRAs have nothing to do with the will and do not go through probate but are paid directly to the beneficiary. There are special rules about IRAs. You can add it to your own or take an immediate distribution but you will have to pay taxes on it. You need to file a claim for the funds but you need to speak with a CPA or financial planner as to whether it makes sense to either liquidate the IRA and take the tax hit or roll the IRA over into your own.

One caveat - were the IRAs payable to you directly or payable first to the estate? If paid to the estate they do need to go through probate first. If paid to you directly then they do not go through probate.