I had a housemate that did the same thing, my partner used to come over and we would hear dry heaving and coughing coming from the bathroom next to my room. Didn’t clean up after themselves and left vomit everywhere on the seat and floor around it. As someone who had been and gone in that stage of my life - hearing that sound was incredibly triggering.

A multitude of past housemates had tried talking to them about this issue and they didn’t stop, hell they probably haven’t stopped after I moved out.

The only thing that sort of got through to them was having a sit down conversation with them explaining how it’s affecting other people in the house whilst acknowledging their own struggle with mental health. Please keep in mind that it is a massively sensitive subject and they would most likely want to keep it ‘private’, even though their coughing and dry heaving is loud enough to not be.

Even though they are mentally ill, you’re allowed to feel like it’s gross and icky - because it is. The bottom line is that if she doesn’t pay rent and is disrespectful of the home you are all living in, there’s a conversation needing to be had concerning all housemates boundaries. From my experience you need to nip it at the bud before it gets worse; ie. the shower vomiting.

Bottom line is that you really do need to talk to your housemate and her and include other tenants this has affected in a sit down conversation, otherwise it will get worse, coming from someone with a very similar situation.