Hornet was looking for her sibling.
She had no idea where Ghost was. Likely nearby, but they were fast. After going through that... opening in Dirtmouth, they'd gotten separated. As in, she took her eyes off her sibling for one second and they were gone. Ghost was definitely here. Possibly...
Fandom - Hollow Knight (The protagonist)
The Knight was a failed vessel-created of God and Void. They were intended to die as they were not pure but survived anyway. They are Hornet's half-sibling, as they share a father. They are completely mute and harness the power...
Hornet, the princess-protector of Hallownest. She's a vaguely humanoid woman, standing on two legs with presumably two arms. Her mask and horns are simply her head. She's never seen without her signature cloak of red, or her silk-threaded needle that she wields as a deadly weapon...