The Hungry Ghosts, by Miguel Flores

From the Penguin Random House website:

A tale of magic, found family, and the power of being yourself—even when the world asks you to change.Witches have been banned from Arrett for years. Which is why Milly has tried to ignore the tingling light that appears in her palm anytime she conjures up a wish. She has too many responsibilities as the oldest girl at St. George’s Orphanage to get caught up in magicks. Sweet, quirky Cilla, though, has always longed for that power, even if it could be dangerous for her. Milly has always kept an eye out for her, but then, in a case of mistaken identity, Cilla is kidnapped by an angry, exiled witch who believes she’s the one with magicks—not Milly. Desperate to bring Cilla back to St. George’s, Milly sets out to find her with a sarcastic young Wind stuck in the form of a cat as her companion. Along the way, they meet an independent young broomstick and gentle giant—and a whole world Milly has never seen before. As she searches high and low for Cilla, one thing becomes clear: she’ll have to face the stirrings of forbidden magicks inside herself in order to rescue a friend who has become more like a sister.