I'm worried about my friend please help

My friend, let call them B, has a bad home life, there dad hits them, mom hates em, today my friend told me that her mom said "I hope you get tiktok famous and commit suicide" and I'm absolutely fuming because she can't say that, my friend told me not to do anything or they will never forgive me, they don't want to be split up from there siblings in foster care, but somethings gotta happen right? What do I do?