How high court will see into this is not the question, the question is that how are you going to challenge her appeal pending before high court.

The point that she already has another house is very much valid and also one of her children is an adult this day, moreover she cannot be described as dependent on your father.

The law is very clear that if your father, a senior citizen was ignored especially after he had transferred all his property in favor of his children and if he had been made to suffer in destitute  then the law will come to his rescue, the cancellation of the gift deed to one of the properties should be viewed legally correct and valid in the eyes of appellate court, provided your lawyer puts up a strong argument in your father's favor. 

Even if the deed does not explicitly say "maintain," High Courts ) have ruled that when a senior citizen transfers property to a family member, it carries an inherent and implied condition of "love, affection, and care" in their old age. Neglecting or abandoning the father effectively voids the gift under Section 23 of the Act.

2)The fact that the gift deed explicitly mentions "out of love and affection" actually works in your father's favor. Courts interpret this phrasing as proof of an emotional, conditional family arrangement, rather than a purely commercial transaction.

3)the law focuses entirely on the survival, shelter, and health of the 75-year-old father. The fact that she possesses another property, and that the deceased son was already gifted a property, weakens her plea of severe destitution.