All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad is His slave and Messenger.
The inheritance of a woman who died leaving behind her two brothers and two sisters should be divided between them as follows: the male twice the share of the female.
So, the inheritance should be divided into six shares, each brother gets two shares and each sister gets one share.
As regards the son of the dead brother, he does not inherit because of the existence of direct brothers of the deceased.
It should be noted that the matter of inheritance is very complex an issue, so a mere Fatwa, which is an answer to the question, is not enough. Rather, the matter should be taken to an Islamic court to look into the case, or it should be presented orally (in person) to the scholars in case there are no Islamic courts. It might be that there is an heir who would not be known except after investigation, and there might also be a will, debts, or other dues that are not known to the heirs. It is known that these rights come in priority over the right of the heirs. Therefore, the inheritance should not be divided without resorting to an Islamic court, if any, in order to fulfill the interests of the dead and the live people.
Allah knows best.