What is the Michigan Law pertaining to Surviving spouse and a living will?

My step-mom passed away and she has a living Will. I am on the Will as the one to make sure her wishes are carried out. My step-Sister is causing a lot of drama over the Will. My mom has only been deceased for 1 month. We are having her Memorial on the 25th of June and wants the item right away that was left to her by her mother. My dad is not ready to let anything go. Is he in his legal right to hold off on distributing the requested items in the Living Will or does he have to do it right away. My dad is the surviving spouse and I would like to know what his rights are pertaining to this matter.