Does my sister have a share, and is a will enough?

My mother owns a property, and my sister and I are her only legal heirs. My father passed away four years ago, and according to Indian customs and rituals, all property-related formalities were completed by my father for my sister and her children. Now, as the property is set to be transferred to me, I am seeking clarification on a few points. Firstly, does my sister have any rights or share in the property? If my mother decides to transfer the property to me, is my sister's signature required for this process? I have been advised by some well-wishers that a will alone is sufficient for me to claim the property. I would appreciate confirmation on whether my sister has any claim and guidance on how to proceed with the property transfer. Additionally, please advise if a will alone is adequate or if other legal steps are needed.