Wings are the symbol of mages, a manifestation of their powers. But magic isn't something easily accepted. People will do anything to be normal. -- YizukiKhons
They appear with the first use of magic, which can happen at any time following the day that a child first recognises that their own actions have consequences beyond themselves. Some say that their size indicates the mage's power. They are made of light, and it is not their size, which is illusory, but the luminosity of them that counts.
When Taerl, aged five, became annoyed at the sudden light in the theatre where she was trying to enjoy the performers, she had no idea the light was her own. Not until a fellow young patron asked her to turn her wings down. It hurt to look at them, they were so bright. She could move them if she thought hard about where they were, and made them stay inside her capelet, where they illuminated the floor underneath.
She'd just wanted to keep her chestnuts warm, and now this had to happen. Stopping the soft flow of force into her chestnuts did nothing to dim her wings. Focussing on them made them shine brighter. Trying to ignore them didn't do much to dim them.