My mom asked for a divorce. My dad made his mother his pension beneficiary — then killed himself. Now my mom and grandma are feuding. Who is right?

https://www.marketwatch.com/story/my-mother-asked-my-father-for-a-divorce-he-replaced-her-with-my-grandmother-as-beneficiary-on-his-pension-then-took-his-own-life-what-should-they-do-2020-02-08?mod=cx_picks&cx_navSource=cx_picks&cx_tag=mw&cx_artPos=7#cxrecs_s\\\

‘My grandmother and mother both have lawyers, and they both say that they are going to get this pension. It’s been dragging on for nearly two years’