Unhygienic sister

Hello folks,

My sister has been living with me for almost a year. I love her and it’s such a blessing to be living with her but some things are really starting to get under my skin. She’s not a very clean person. She doesn’t shower or wash her hands. She’ll touch communal food after coughing into her hands, cough/sneeze into the open, blow her nose in the bathroom sink... She has PTSD (we both do), so it can be especially tricky talking to her about this stuff. My boyfriend is a very clean, particular person, so he has a really hard time dealing with this too.

Please please please help.