ONLY that she acquired from our father and which was his self earned property? This is because of him being evil in his intentions and also because he syphoned off some money from bank and P.O. investments. My father had mentioned as three equal shares but our brother does not want the property to be sold in future and us to have our share. What does our 84 year old mother do in such circumstances as she wants to protect our interests?
In the absence of Will no one will come to know what is written in Will.
Therefore in my opinion, before some adverse incidence takes place, it would be better to have a partition of the property, since it your father's self acquired property, you, your other sister and your mother are entitled to an equal share in the property along with your brother, therefore you people can seek 3/4th share in the property, if he is not agreeing, you may file a partition suit seeking your shares in it.
This may be better solution for the present.