You can't choose your family

My dad passed away nearly five years ago. Since then, I feel like my mom's life has gone pretty steadily downhill, though not in the usual sense. After my dad died, my unemployed sister moved in with her to "take care of mom". My sister is a hoarder, and quite possibly bi-polar. So, my mom may be slightly less lonely, but her house is now filled with junk. Trinkets are wrapped in plastic grocery store bags, covered in dust and piled haphazardly throughout the house. There is a two foot wide path from the front door through the living and dining room to the kitchen through the mess. I'm not sure where my sister sleeps, as her bedroom cannot even be entered, it's so filled with utter crap. Now, when I say my mom is slightly less lonely, it's because my sister isn't great company. She says she's too busy to bathe regularly, she goes off on these screamy-shouty tantrums; my mom hides in her own bedroom. Besides that, my mom can't have company over to the house. I'm pondering what I can do. My mom doesn't like the situation, but she's too worried about my sister's well-being to move into Senior Housing. Mom is of the generation that thinks getting psychiactric care makes you "untouchable" for employment or otherwise. These are the days I wish I lived far, far away... I'll figure it out. Thanks for letting me vent. Maybe now I can sleep.