MC words make sense...unfortunately the original body owner speak volume, we and the characters in the sotyr knew she was lost in love with the prince and incredibly jealous, so much to risk her own skin with the harassment to the saint.
Unfortunately that makes the whole dialogue in this chapter dumb, as everyone knows the MC is somewhat different, with the crown prince realizing it istantly, she tried to stick to him like glue after all, is weirder that her family ddn't still recognize the difference.
If she wanted to be together with the prince all she had to do was showing the power she is doing now, of course anybody sane would think she sold her soul and became possessed or simply swapped with someone else.
Is like the author thinks the readers are as stupid as the characters he made up.