Glitch is Lavender Eyes's Unlucky Childhood FriendThink about it: he was apparently devoted to her, was implied to have known her when she was younger, and seems to be very protective of her daughter.
The Prophecy about the sisters was flip-floppedThe prophecy said that "one to darkness she be drawn/and one to light she be shown." Everyone in the series seems to think DG was the light and Azkadellia was the darkness, which makes sense on the surface. But DG is the one who originally heard the Witch's call—Az only heard her after DG pointed it out. Also, while Azkadellia is the evil sister, in the end DG brings her back by showing her the light. So the prophecy was about the sisters, but switched around: DG was the one drawn to darkness and Azkadellia was the one shown to the light.