This is Reikimizu, one of the dragon river spirits in Japan. But more importantly, she is Fafnear Haventhrone's mother.

A kind spirit, she causes calmness and serenity to those around her. Gentle and soft spoken, she was never one to raise her voice, or get violent. Her only passion in life was to care for her river, letting its waters sustain and heal the land around it.
After a particularly bad earthquake caused pollution to seep into her river, she left to gather pure ice from the northlands, knowing the pure ice would boost her magic and help clean the waters. While there, she was set on by a large Norse Dragon. She managed to escape, but would be bring back more than just pure ice.

Sometime after Fafnear's hatching, the dragoness was hunted and killed for her golden whiskers.