Shatter Me (Shatter Me: E#1) by Tahereh Mafi

From Storytide:

The gripping first installment in global bestselling author Tahereh Mafi’s epic, romantic Shatter Me series.

One touch is all it takes. One touch, and Juliette Ferrars can leave a fully grown man gasping for air. One touch, and she can kill.

No one knows why Juliette has such incredible power. It feels like a curse, a burden that one person alone could never bear. But The Reestablishment sees it as a gift, sees her as an opportunity. An opportunity for a deadly weapon.

Juliette has never fought for herself before. But when she’s reunited with the one person who ever cared about her, she finds a strength she never knew she had.