Can I file for a Letter of Administration regarding my mother's Estate?

I am trying to apply for the 9/11 Fund for my deceased mother. I have been told that because she was married at the time of her passing her husband would be entitled. When my mother passed away, she was married. My mother did not have a Will. Not long after her passing, her surviving spouse passed away as well. They have no children together. I am not sure if my mothers husband had any kids anyway. In this situation, am I entitled to file for Administrator of my mother's estate? If my mother's husband had any children, are they entitled to anything? Are they a priority? When my mother passed away, she had AARP Life Insurance in which she named myself and her husband on. Since he has passed, who is next to receive, if any?