Who is next of kin

My father died 7 years ago, his mother died this past month. My mother remarried. Their are 4 remaining living heirs of my father. My grandmother named my father as beneficiary and never changed it, who would be the next of kin to my father? Everyone I've talked to said the kids since mother remarried, what does the law's of Florida say? My father did not have a trust.

I think you kids get all his stuff. Talk to a lawyer.