Heat Stroke (Weather Warden Book 2) by Rachel Caine
Joanne is “reborn” as a djinn. She and her lover David are still on the run from the thoroughly corrupt Wardens.
They realize that a great imbalance in the natural world is endangering both djinn and humankind by functioning as a weak spot through which demons can enter this world. The imbalance was caused by David drawing upon his own life force to save Joanne and recreate her as a djinn. So his life is in danger, too.
They must repair the damage. However, an evil woman and her adolescent son “claim” Joanne as their djinn. She finds herself stuck in a bottle, let out only to obey their orders. Some of the funniest scenes involve Joanne’s exasperation at having to manage her icky teenage “master.” She must win her freedom and rejoin David in their quest to balance the earth’s energies.