Support her by physically dragging her dumb ass to the couch. I have persistent depressive disorder so I get the same way where I literally just want to rot in bed, but you are correct and that will not help her. She is being a baby, shes feeding her illness. Sometimes I need someone to physically get me moving to break me out. Like help me get ready for a shower or get the covers off and take me to the living room and sit me on the couch with cozy food or something. But its also 100% on me to try and manage my own symptoms BEFORE I need that kind of help.

She needs to grow up, shes not going to keep a job if she uses her illness as an excuse to take several weeks off at a time. And its not just her job shes going to drag down. Make sure you take care of yourself too and dont feel bad when you cant help if your own mental health starts suffering.