Part of me came to this thread hoping to find that someone would have a similar situation to me, someone I could relate to. But that doesn't seem to be the case

Part of me came to this thread hoping to find that someone would have a similar situation to me, someone I could relate to. But that doesn't seem to be the case. I'm not estranged from my parents, but my sister is. And it's definitely less typical that most cases. We had a very stable upbringing, no abusive parents, nothing like that. Our parents got divorced when we were both very young (3 and 4), but it was always amicable between them. It's kind of complicated, but here's the gist: Essentially, when she graduated university, she got a job and moved away. She met this guy who seemed really great and very soon after she started talking to me about "this great book she was reading", and a podcast by the author, and basically she was getting really into this thing. Some of you may be familiar with him, his name is Stefan Molyneux. I just googled him to verify the spelling and apparently he's now considered a "far-right white supremacist", which is new to me but unsurprising. Back then I would have just considered him a "very strongly ideological anarcho-capitalist/libertarian", the "taxation is literally violence" type. There's a lot that could be said about him but that's beside the point. Suffice to say there's a section on his Wikipedia page titled "Cult accusations". So back then, probably 7-8 years ago, his content was more focused on his libertarian ideals, but also various "self-help/improve your life"-type topics. This was more what my sister was into. One topic in particular is "De-FOOing" (Family of Origin). Essentially, cut off ties to your family. He gives lots of very compelling reasons why your family is terrible and you shouldn't talk to them anymore, in his typical intelligent-sounding charismatic cult-leader way. Fast-forward a year or two, she's still getting along with everyone, but she definitely seemed to be thinking differently. A few minor things happened between her and my mom that she wasn't too happy about, and then my mom made the mistake of driving over to her place unannounced. Which, yeah, she probably shouldn't have done. But my sister responded by sending her a formal letter basically saying "don't ever come here again, and don't ever talk to me again or I'll be calling the police" and I think it was even signed by a lawyer or something. Basically just shy of a restraining order. This was really out of nowhere. I didn't really know how to react so I didn't say anything to her out of fear that she might do the same to me... Not long after that she moved across the country without telling anyone except my dad, cut off communication with basically everyone she knew, including all of her friends and family (except my dad briefly, I think she called him once after moving). I haven't seen her in 6 years, and no one has heard from since not long after that. The last communication I had with her was on my birthday over 5 years ago where she wished me a happy birthday and was happy that I had found a job after graduating college. Her birthday is 8 days after mine. I wished her a happy birthday, got no reply, and haven't heard from her since. We got along great and there's no reason I can think of that she would want to cut ties with me, and I think that makes it worse. Sometimes the pain is hard to deal with. Our grandmother died a little over a month ago, and I honestly think it was more painful for me to know that she never got to see my sister again, than her death actually was. She lived across the street from us our entire childhood, would babysit us every morning when our dad was gone to work. She loved us with all her heart. I can't imagine the pain she must have felt knowing she wouldn't come back before the end. It just tears me apart. I find myself regularly wondering whether I'll ever see her again. Whether she's even still alive. Would I even find out if she died? Is she even still in this country? God I hope she comes back soon. Or at the very least while our parents are still alive. I don't even really know what I expect to get out of posting this, but it's a small relief to finally get some of it off my chest.