in case of no will she can

Is your grand father alive? If he is not alive and had not made a WILL, then your grand mother(if she is alive), father, his brothers & sisters will have equal share in the property. If he had made a WILL , then the property would devolve as per the contents of the WILL.

Is your grand father alive? If no, has he left any will respecting his property? If he died without making a will then your father's sister has a share equal to the share of your father in the self earned property of your grand father.

Fir disclose how does the property fall in your father's share?

If the same devolves upon Will on your father, then your father can bequeath it to any one he chooses.

In case grandfather is not alive and has not left behind any Will, then your grandmother (if alive) ,father and his sisters have equal share.

since it was your grand father property on his demise all his children would have equal share in the property . your father sisters have equal share in the said property

If your grandfather has died intestate, then all his children will have equal share on his self earned property.