Am I legally entitled to any portion of my deceased parents'' assets (in NJ)?

My mother, who lived in New Jersey, died without a will several years ago. All the family "assets" (for lack of a better word) were jointly owned by her and her husband, so he apparently became the sole owner after her death. These assets were basically a house, bank accounts, perhaps a retirement account, etc. I am the adult biological child of that couple. My father remarried. Then, he died and left everything to his wife (i.e., my stepmother) via a will and perhaps joint ownership, etc. Am I entitled to any portion of my biological parents'' assets, or am I basically out of luck? What are my chances if I choose to fight this thing legally? If I wait until my stepmother passes away, would I have better legal grounds (even if she cuts me out of her will)? Thanks for your help!