(very long thread, hopefully it doesn't get deleted any time soon)
TLDR: That girl Corey got mad at and subtweeted about Michelle because Corey helped her find receipts for some drama video but Michelle never even bothers to even ask how she's doing so Corey took that as Michelle using her. Michelle says she's got her own shit IRL to deal with (depression, anxiety, her child, etc). They're a part of some group chat with BTS which Michelle left before that subtweet was posted.
So when Michelle got on YouNow, she basically said outright that BTS is sicking that girl Corey on Michelle to fight BTS's battle for her and BTS has been in Corey's ear telling her negative shit about Michelle. BTS has had a problem with Michelle for a while and people had been sending Michelle screenshots of BTS talking shit about her. I think she said BTS's beef with her stems from Michelle unfollowing her on Twitter which Michelle denied and blamed BTS for blocking Michelle first and unblocking her, causing the unfollow. Regardless, BTS is a passive aggressive bully and she needs to tone it the fuck down. If you're going to be a cunt, then be a cunt. No need to tip toe around.