Has anyone experienced a daughter sabatoging their mother's care?

I've witnessed my sister in law's selfishness in numerous situations in the past. Threatening not to pick up her mother for a holiday if her mother had contact with her separated husband. Slapping her mother's hand if she touched the thermostat when it was 54 degrees inside during winter after my mother in law paid to fill daughter's oil tank, taking my mother in laws' money, not providing proper food. It is Emotional/Financial Elder Abuse. Fortunately, my MIL no longer goes to her daughter's home, and my husband had to exert POA as her dementia has worsened so the gravy train to my sisterinlaw has stopped.
My SIL went from calling her mother "Mother" to calling her "Mommy" overnight..... quite bazaar. Especially when her childhood friend said she always called her Mother.. whats with the "Mommy". When my MIL was in rehab requiring sneakers, I went into the physical therapy room to find my MIL wearing high heels! ARRRGGGGGH! Doctor ordered low sodium diet for CHF, daughter refuses to listen. MIL had GI bleed requiring blood transfusion, daughter said to my husband to just let her go home and let nature take its course, that she just wanted money left. Daughter tells live in caregiver to let her mommy (93 yr old) wait up for her when she travels for her weekend when she normally goes to bed at 8:00 pm, then keeps her mommy up until 11:00 pm.
The real telltale sign of this sabotage was after a schedule of care was made for continuity of care, my sister in law removed it... no where to be found. I find it so sickening.......as she puts on a "show" in front of others to be the "devoted attentive daughter" We can't keep the daughter away from her mother, and actually the mother has created the daughter to be the narcissist she is.
Has anyone had a family member who sabatoges their parent's care?