Do illegitimate children have same rights as legitimate children?
Not necessarily. Although the laws of the state where your grandparents live might be different, in California all of the children (both legitimate and illegitimate) inherit equally IF the relevant parent “acknowledged” them during his or her lifetime. If the parent did not want any of the illegitimate children to inherit, s/he would have to specifically disinherit them in his/her will (“I leave nothing to my other 12 children, namely A, B, C, D, etc.”). The information you obtain at this site is not, nor is it intended to be, legal advice. You should consult an attorney for individual advice regarding your own situation.