If your father has no other spouses or children, and his parents died before him, and any debts and wills have been settled.
Your mother gets 1/8th since she has children:
Quran 4:12 And for the wives is one fourth if you leave no child.
But if you leave a child, then for them is an eighth of what you
leave, after any bequest you [may have] made or debt.
The presence of a son among children blocks farther relatives. The remainder is divided among the children so that a son gets twice the share of a daughter.
Quran 4:11 Allah instructs you concerning your children: for the
male, what is equal to the share of two females.
So, your mother would get 12.5% of the total, you and your brother would get 29.16% each and the sisters would get 14.58% each to sum to a total of 100%.