So sorry for your loss.
You should check the terms and conditions of the pass to see if it is transferable.
I think this is the correct link for it. If not go to the website for the correct one.
https://www.ezpassnj.com/en/about/terms.shtml
Laws are different in each country and jurisdiction, since you have not told us where you live (you do not have to give specific address but city, state and country would be nice) it is impossible to help you except in the most basic way - such as suggesting legal aid.