Cinders Like Glass by Clarissa Kae

A classic Cinderella fairytale with a Victorian Twist.

With her guiding hand, Lady Ada turns the mundane into the magnificent, lumps of charcoal into beautiful sketches—and second-hand clothes into gorgeous gowns. Only her debilitating stutter is beyond reach.
When her cruel brother is accused of treason, he threatens her—she must help him, or be thrown into an asylum, claiming her stutter as evidence of an unsound mind.
Like a rabid dog, the Duke of Girard is consumed with uncovering the traitorous plot surrounding Lady Ada’s brother. She holds the key to solving the mystery, but is unable to speak.
He’s determined to interrogate the woman, but the longer he’s in her company, the more kind he becomes. With Lady Ada’s brother on the loose, can the Duke of Girard win her trust—and her heart—in time to save the queen?