Need advice on a family matter. Long read but please help!

I will try to keep this as short as possible! Thank you for reading. Backstory: I (35) am a healthy, successful, happily married woman with good friends and good relationships with my birth family (mom, dad, bro). I also have a sister who was abusive towards me as a child. We got along fairly ok for a short period in my early twenties. As an adult I attempted to maintain a relationship with her but it got increasingly more difficult. I don’t mind maintaining relationships with difficult people and truly tried my best. When she became a mother ten years ago, her behavior became much worse and continued to deteriorate as time went on. It started as a PPD diagnosis that she refused to seek help for and grew into full blown agoraphobia. Without seeking any help for her increasingly poor mental health state she eventually became paranoid, thinking every one was jealous of her, she would straight up lie (about her past, about me and my family, etc). I do have to say I am pretty sure she believed these lies. To speak on the severity of the lies, she once tried to convince me I had been diagnosed with BPD, which I had not, and when questioned about it, created a whole scenario even including an “Asian doctor” which never took place. She eventually became so irrational it was difficult to even hold a simple conversation with her. Not without lack of trying on my part. She began alienating herself from the world (no friends, no extended family) and eventually forced (or maybe not?) my BIL to stop interacting with all of his friends. She even tried to “cut off” her in laws at some point at which my parents, brother and I stepped in and said, “enough is enough!” Anytime we brought up her mental health state she would project it on us, saying we were crazy and swore that she was “graceful and grateful” after the birth of her children, when she was quite literally a raging, crying, scared person every single day. She had no recollection of the doctors saying she had suffered from PPD. My family tried for a long time to get her to seek help and even tried to discuss it with her and my bil. We all had really close relationships with her children who we loved and spent tons of quality time with. I cannot describe how genuine and loving my niece/nephews relationship was with myself and their grandparents. There were no issues, we loved them, they loved us. It was a picture perfect loving family relationship. When I got married everything fell apart. My sister went out of her way to ruin every single event leading up to my marriage. It got very bad. I’ll leave it at that. She seemed to now focus her absolute hatred on me, my husband (who I’d already been living with for 8 years) and my mother. She hated my mother, there is simply no better way to describe it. She’s scream at her and say absolutely terrible things to her. Once Covid came, it got EVEN worse. Her paranoia was just, a lot. Still, my family remained as supportive as possible, but it was hard. She had attempted to control our every move, getting angry that we were not taking it seriously enough. With us having elderly parents, we all took it VERY seriously, we just didn’t share her overwhelming fear of it. We would try to remind her to take it easy, that everything was gonna be OK. She thought this meant we were being too carefree. We followed all mandated procedures. In time, she cut us all off. Every one. Her mom, dad, siblings, cousins, every one. I have to be honest here. Life without my sister for the last year has been a heaven I cannot even describe. I have learned so much about myself and how detrimental having her in my life was. I never want to speak to her again. Just the thought of never HAVING to speak to her again, makes me feel peace. I cannot fully describe how much better for me it has been to not constantly have this toxicity in my life. So here is my problem. . . I don’t know if her children are ok. I miss them like crazy. I want them in my life but not her? Which I know isn’t fair. I’m not sure that she is properly caring for them. I worry she’ll abuse them as she abused me when I was a child. I have tried to call to get her a psych eval and even called CPS to ask their advice. But without proof of abuse, there is no further action I can take. I just have no clue what to do and it kills me. Just sitting here having no clue if my nieces/nephews are locked up in a closet somewhere or being physically abused is just killing me. Trying to reason with her is absolutely not an option and there are no mutual family /friends that can assure me the kids are ok. I try to trust that everything will be ok but it’s really hard. Any advice would be greatly appreciated. Thank you.

Hi SadAunt, Apologies to you, too, for the long wait! Actually, I think you've already DONE exactly what you needed to do. Before I get really stuck in (tomorrow), though, let's just check: Tell me EVERYTHING you said to CPS and he/she said back to you, please? Preferably in conversation order. It doesn't have to be verbatim, just everything you remember (including all the impressions you got).

Why do you want that information? Do you think they should have done more ?

Hi, No, it's because I have "skills" and want to see if I can pick up on anything, not JUST how seriously they sounded in how they were taking it/you. For example: you don't know that you're not the only one who's called them about her (er) "mothering". PS: Maybe have a little stroll around my threads on various posts to get an idea of what I mean so as to feel perfectly comfortable with my questions?