death of partner who has kids from exmarriage

In CA, if a woman (never married, no kids) marries a man who has kids from exmarriage and they have commom kids later. What will happen to the property they buy after marriage if he dies first?

Is it possible that the property goes to longer living partner completely and only after she dies the property will go to kids by drafting a prenups or other legal ways? Is there any legal protection in CA protects the second marriage's longer living one from kids from exmarriage?

Thanks.