My son suggested the name.  We searched it on the web and found only this Dungeons & Dragons definition.  Who could resist?  “The threadmistress is an urban magical savant with an eccentric power over thread. Her touch awakens it as her magic weaves it into patterns and a weapon for use against her foes. She is no mere tailor, but a strangely gifted witch whose [quilting] hobby is far from innocent.”