<human>: So my mom just calls me and hits me with this huge random ass news.

When my dad was 9, his mother and father got divorced. However, his father remarried a new woman named Betty a year later when he was 10.

So six months after they're married, they move from the USA to Japan and my father lived his childhood in Japan. His father worked for the NSA and still had a house in the USA and had enough money to have a place in Japan and then later (in addition) Hawaii. So they were pretty well off. When his father retired, he started a commercial glass installation business that was doing solid.

When my dad's father died, he left the business and all his house and valuables to Betty(his wife) to distribute anything she basically wanted to however she wanted. She took virtually everything except a small house in Virginia and split it between my dad and his brother.

Fast forward all these years, my parents still live in Virginia in the same house basically just living within their means. 

Anyway, so the crazy stuff is now:

My mom calls me and tells me she figured out at the gravesite today that my Dad's father had married his niece, Betty. So my father's cousin was his new stepmom all those years. Fucking batshit.

However, she shouldn't have been given everything with her marriage being illegal and void, right?

Condense the text into a few key points
<bot>: My dad's stepmom turned out to be his cousin after not knowing for like 38 years. He wants to know if the stuff she got in the death of his father is rightfully hers.