Page "Crystal (comics)" Paragraph 13

When Black Bolt attempted to set off an explosion that would spread the Terrigen Mists across the galaxy, reasoning that this action would render all equal, Crystal defied his orders and risked her life to take Lockjaw to confront him, disabling the Terrigen qualities of the explosion and convincing Black Bolt that the powers that would be created by his plan would cause more harm than good.

Although Black Bolt acknowledged her wisdom, an attack by Vulcan meant that Black Bolt was kept too busy to accompany Crystal and Lockjaw when they were forced to flee before the bomb — now a simple explosive device — went off, apparently killing Black Bolt and Vulcan.

After some time with Medusa ruling in Black Bolt's stead, he is resurrected and returns to the throne.

Shortly thereafter, Black Bolt makes a decree that the Inhumans would return to Earth, leaving Ronan the Accuser in charge of the empire ; Crystal is given the choice to leave with the royal family or stay by her husband.

She decides to stay.