A miscalculation, perhaps. She believed Claire would value her life over her percieved duty as a noble, and that their feelings for each other would seal the deal.I have to wonder if Rae truly believed Claire would follow her plan. Above all things, Claire was proud of her nobility and her obligations as a noble. It's one of the things that made Rae fall in love with her in the first place.
Was she thinking that Claire's life meant more to her than her honor or was she merely hoping against hope that that would be the case?
She fell in love with her for her pride and convictions, but it seems even Rae underestimated just how deep Claire's conviction runs...