Problem isn't that, my guess is that Rachel won't even get a chance. Every time the crown prince ask her if she really did everything. My guess is that he knows it is all done by Marie. Especially when it came to the baking. At this point I would put my money on the fact that he thinks she is a liar.
But still I felt like if the crown prince didn't know it's Marie that has done all those things then the deal between Marie and Rachel is unfair. Rachel will not keep her word I feel like she'll just confess it's not her if she's cornered by the crown prince or by the commander
True but also I just thought of something, there is no way to get rid of Marie so easily within the palace because everyone knows that the crown prince is interested or fond of her, it's why she is not bullied. Sadly it would be best to "let he go" and then kill her outside. Or maybe not though Rachel seriously doesn't seem to smart with Marie having to help her with everything.
Well the problem is will Rachel do her part of the deal? I can just imagine what she'll do if she's crown as the empress most likely she'll kill Marie in order to hide her secret/ to preserve her 'wisdom' as not to ruin her reputation