Payday loans in the US can go from 100-600% APR. The upper limit depends on the state. I seen many people take these loans and go down the same path as her.
With the finfluencers on YT and tiktok selling courses, I'm pretty sure you don't need a license to make money off of your alleged financial expertise. You may have to disclaim "not financial advice", but that won't stop the sheep from pretending it is.
Hoarding money in cash and letting it depreciate instead of investing via HISA, bonds, or any other safe security is a major sign of financial PTSD. I feel so bad for the dad.