Hold on, now that I think about it more... while they could be cataloged as some sort of family, they aren't sisters.
Hornet was born of Herrah and the pale king.
Lace was created by mother Silk.
Yeah but they treat each other more like sisters, fighting for the mother affection, i was thinking about something but amm finish the game first and we can talk more about why i think about this too x3
