division of self-acquired property by a senior citizen

My father bought an apartment and put it on my mother's name who was a housewife when she was alive and then before she can die, she gave an affidavit returning the apartment to dad. My younger sister who is a lawyer married claiming one fourth share in the property. My dad is 75 years. She says she will file a litigation case to evict him. I am unmarried daughter living with him. can my aged father disinherit her, as it dad's self-acquired property. She has been harassing dad who is a diabetic and high bp. She has never took care of my parents, in fact she harassed them. According to the Supreme Court ruling elderly parents can deny a share to negligent children. Can my dad invoke that section according to the supreme court ruling which was published in the leading newspaper a week ago?