On the Accidental Wings of Dragons by Julie Wetzel (2015) Crimson Tree Publishing

Paranormal fantasy romance.  A woman, whose brother is the king of dragons, is thrown into a dungeon.  There is a man chained to the wall.  She has no voice and cannot speak the magic that could save them, but still, she unchains him, and they escape.  Only she is attracted so strongly to him it is a distraction as they run for their lives.