If you're evicting someone considered a "roomate" not on the lease in the state of PA what is the minimal?

amount of time needed to be given in the eviction letter when the reasoning for eviction is due to behavioral problems and violence? Basically my sister allowed my other sister to move in with her for a few months until she could get her life together after problems she was having and since she has moved in, she's displayed serious signs of instability, drinking excessively and becoming extremely violent when drinking. Last incident she called 911 on herself and then proceeded to assault a police officer and was arrested. My sister fears for her safety and wants her to leave. She talked to her landlord and the landlord said that since she was never put on the lease it's my sister who needs to write her the eviction notice acting as Sub-landlord and Sub-tenant. I was trying to help her write up this notice to quit and vacate but I was having a hard time finding an exact time period. Some sites say she has to give 15 days notice, others say 30 days notice. She has given my sister rent while living there, so it's not an eviction due to non-payment of funds and more an issue of safety and violence and just needing her to get out as soon as possible. Does anyone know the minimal amount of time that can be given in a notice given to her because she said she will not leave willingly?