This is the worst book Carolyn Meyer had ever written. It is Mary Stuart's own telling. And all her say is "I'm innocent pure lady maliciously ill treated". I don't believe you, Mary.
I don't think Mary is innocent of Darnly's murder nor I think Mary is forced to marry Bothwell. She had to her men to kill her own husband and joyfully married to Bothwell.
I recommend Jean Plaidy's "Royal Road to Fotheringhay".