Girl With the Staff GWS

Long ago there were five sacred warriors, one for the sword, bow, fan, mace, and staff. They together brought peace and prosperity to our world. Now, many years later, they are reborn. My lineage dates back to that of the staff wielder. But, it's not as simple as that.
...
I have a sister.
A twin sister.
And only one of us can wield the sacred staff.