Hi
the general rule that if a person dies intestate his property shall be divided between the heirs equally.
The property was in the name of your father and house was constructed on it by mother,however the property is still in the name of your diseased father.
Your mom and your sister along with you , you 4 are the legal heirs of your father , each one has an equal share in the property.
If the property was not transferred in your mother's name , now she has no right to give you a gift in the whole property, she has only a share of 1/4th right in the property.
Your two sisters too have the one each right .
it is sad to say that your mother has no title or right to transfer the property in your name, she can transfer only her share in the property.
her share can be transferred in to your child's name through a gift deed , and you can transfer your right to the child's name also.
The transfer of the sister's share property is possible only with their consent, through a registered a release/relinquishment or gift deed