Not sure if this is the right place to post but I am growing desperate and incredibly stressed. I am not asking for a diagnosis just advice on how to approach her about getting help. 

My sister has been acting strange for the past few months. She has been dwelling on past trauma, dealing with housing instability, sitting at home all day (no job/school), and smoking A LOT of weed. I think this has all come to a breaking point and she started having delusions/paranoid thinking. I had started to worry a lot about her when she would text me things about our family and trauma that didn’t make any sense. Then she started mass posting on her social media story (like literally several dozen posts of random screenshots, pictures, some of the same ones posted several times) and sending me weird things with no context. I won’t go into details but there was an incident that caused my mom to take her to an urgent care mental health clinic. She was diagnosed with psychosis and was checked into a psych ward where she unfortunately had a terrible experience.

She checked out after about a week without her condition having improved at all. After she was evaluated by a psychiatrist she was found to be stable (she seems to know what kind of things are acceptable to tell people and which of her thoughts would cause people concern). There has been no follow up or medication prescribed. She went straight back to doing nothing all day except smoking weed and manically posting on social media. Several friends and family members have reached out to ask if she’s okay because of how concerned they are. However, she refuses to see a therapist or get any kind of help. Whenever myself or my mom try to approach her about it, she is incredibly irritable, says hurtful things, and insists that she’s not crazy (obviously we have never used this term to or about her). So we cannot do anything besides try not to upset her and act like everything is normal, which makes me incredibly sad. This situation is not sustainable as she is still manic posting and dwelling on trauma and I’m worried that she will become unstable or have a psychotic break again. Is there anyone who has dealt with a similar situation and can give advice on how to help her? Or even better-has anyone dealt with what she’s going through and can give insight on the kind of support that helped you? 

TLDR: sister’s dealing with a rough time mentally/emotionally but refuses to get any help