If my father divorced my mother 14 years ago and remarried the same year then died 3 years later, is his second wife entitled to any of my father's estate?

His second spouse is entitled to only the asset accumulation during the second marriage, unless your father willed his estate to her, then she is entitled to the whoole estate. As to the asset accumulation he held after the divorce and if the assets can be segrated, then his children would be entitled to those assets, including the children of any deceased child of the deceased father.