Transfer of property rights

My father left us without a will. The remaining surviving members are my mother, sister and myself. The land parcel is about 30 cents and has a house in its centre. Due to internal issues with my sister, me and my mother are unable to mutate the property equally between the three of us. She refuses to agree to my mother's suggestion to mutate the land parcel and house separately. My plan is to apply first for a legal heir certificate and transfer the property to all our names. Therefrom, since mutation can happen only on mutual consent because there is a house, where me and my mother lives, in the centre, I am exploring other possibilities. Can my mother write a will giving her share to me and my sister and if she does it is based only on the legal heir certificate. Does that hold good in a court of law? That is, assume she transfers her 10 cents through a will to me and my sister equally. Is this valid in a court of law since the property has not been mutated and her right to property is based only on the legal heir certificate? By doing so, we would be able to avoid court and keep this private.