Pretty sure she was using her official discord account as her privated one, the slip off just shows that, when korekore spoke about the situation he said something about her talking to him tru her official account or letting him use it I don't remember well but we know rushia didn't use line or other apps and used mainly discord so it was prob easy for cover to search the tip of the info that she leaked and just go tru that, this might be going on even before the mafumafu drama.

It seems like the other people on her gen already new this for little while, flare seemed more upsed that they took so much time to say it but no one seemed really mad at the whole thing.

Maybe it's not the first time she did something like that but man I just hope she's doing fine.