How to legally fire a caregiver when she has conned her way into my Mom and sisters life.

They are blind at what she is. Mother has dementia and she's in denial after losing my dad she's at home instead of a retirement facility. We have a private sitter who enables and baby's mother and treats me like she has adopted my mother and she does whatever she wants and tells me it's the way it is and she has control to do whatever she wants whether I like it or not.