... no. If I speak truly, they will beat me, or imprison me. [They wouldn't kill her -- she is valuable enough that she is worth more alive.]
And I cannot leave. [So, yes, nothing she can do about her situation.] ... they will marry me off to the king's uncle. [So that'll be that. Granted, Littlefinger has promised to get her out of there... but she's not holding her breath for it.]