The Dragon Twins by Michelle Madow

Magic. Romance. Adventure.
And twists you’ll never see coming.
Twin sisters Gemma and Mira couldn’t be more different.

Mira loves surfing with her friends. Gemma loves reading. Mira dates a new guy every month. Gemma rarely meets anyone she’s interested in. Mira doesn’t believe in magic. Gemma’s always had faith in its existence.
According to legend, Gemma and Mira are descended from witches. But they’ve never been able to use magic.
On their seventeenth birthday, everything changes. They’re gifted with power over the elements, and right after receiving their magic, they’re tracked down and attacked by an ancient monster. They would have died, if not for Mira’s boyfriend Ethan showing up to save the day.

It turns out that Ethan has magic, too. He’s a dragon shifter from a dark realm, and he’s sworn to protect the twins from whoever’s hunting them down.
With monsters relentlessly chasing them, the three of them go on the run, pausing only to sleep—and to allow Ethan to teach them how to master their magic. Since they’re stuck together, Gemma has to try harder than ever to keep her deepest secret from her twin—she’s been in love with Mira’s boyfriend for months. Sometimes, she swears Ethan feels the same.

But Gemma’s feelings for Ethan should be the last thing on her mind, because whoever’s hunting them has dark magic so impossibly strong that even the most powerful supernaturals are running scared. With nowhere left to hide and time running out, the twins race to discover the truth behind their heritage so they can fight back—even if that means committing the ultimate act of betrayal: of each other.