The Fairy Rebel by Lynne Reid Banks
Tikki wants to give her new human friend, Jan, a precious gift. BUT - fairies are forbidden to touch humans, still less make magic for them!
The Fairy Queen says that all humans want are favours. And only she has the power to give - or take - life. Tikki doesn't care!
Eight years later, Jan and her fairy child discover that Tikki is being cruelly punished. They must rescue her. But how will they ever free the fairy from the deadly power of the Tyrant Queen...?