Anchored. The Anchored Series, #1

Every time Alora goes to sleep, she wakes up on another world, a magical world, a world that's about to collide with Earth in a very big way. Alora's the only person with the power save them both, only, she's not sure she should.  Alora's life has been anything but magical. Since her parents died, she and her brother have been on the run from a creepy, doggedly determined social worker. In a few more months she turns eighteen, but until then, they're stuck hiding.
It's hardly surprising that she dreams every single night of another world, Terra, where she possesses telekinetic powers. What Alora can't explain is how, when she breaks her arm in her dreams, she wakes up with the same (very real) injury on Earth. And if her dreams aren't real, shouldn't they be more fun? Since only men on Terra are supposed to be able to move things with their minds, Alora spends all her time there hiding her powers.
But when her best friend on Terra is threatened, Alora uses her powers to save him, inadvertently killing the attacker. The next day on Earth, the exact same man she killed on Terra walks into her workplace.