Can fathers sister claim share in mothers property after fathers death

I want some clarification about my grand mothers property. My grand father 1.5 acre gifted fo my grand mother and my grand father expired on behalf of my grand father another property 1.7 acres changed to my grand mother (she is live), my father sister got married 50 years back now she is trying my grand mother property. what is the chance to get property to my father and my father sister.