But she is the only one to know martial arts I believe?
Viewing post in Echoes of Amber: Kogasa's Forge Retrospect comments
So does Kasen, and she's a powerful oni hermit. She's way above Meiling in every way.
And the oni species in general is known for having physical strength beyond other youkai species.
Meiling, meanwhile, couldn't beat a lone ice fairy. She has NEVER defeated a single named character in canon. She lost ALL her onscreen fights. She knows martial arts, but those martial arts couldn't win against the magic of an ice fairy. So there's NO WAY she could possibly win against an Extra Boss.