I need to help advise my mom financially. She’s convinced the market will crash

Please mods don’t delete this. I need help.

My 64 yo mom has $500k tied up in a saving count. Ik that is insane but she convinced the market will crash. She cites something from the Bible that I honestly don’t remember/understand.

I just emailed my dad who has been quite successful with stock for advice. At best I can convince my mom to invest in the S&P500. Ik that isn’t a stock but it’s something at least against inflation. Is there any way I can convince her the market isn’t going to crash?

I’ve always been taught the market will go back up regardless but idk how to convey that to someone who lost everything in the 2008 crash. Seriously anything helps