The thing Khione hated most about demigods was how they were so utterly devoted to the Olympians. She would never invoke those who had done nothing for her.
That was why she threw her tab in with Gaea. The Olympians ignored her. Neglected her. If she faded, they wouldn't even look twice. Khione hated gods. Not her father, he was her father. Not the other minor gods. The Olympians, with their thrones and their mountain top above the Empire state building and their stuck-up attitude.
If you asked a mortal about Khione, they'd say "Who?" and blink. That wasn't the case with Athena or Poseidon or whoever. Even Hades and Hestia were recognized. Not her.
The gods had treated her badly for millennia. When Gaea asked, Khione didn't think twice.