Marl was in a pinch because someone was aiming for her to be his wife. As a princess, her royal obligation forced her to complied with that demand as it would have less risk considering the other party. But Marl was a free spirit, and so she tried to find a candidate to be her one-and-only husband, get laid (aka lose her virginity so she won't be betrothed to the other guy), and devotes herself to her husband.
Marl has a special ability (almost intuition-like) to find the thing she wants to find (or at least the clues that will bring her to her target), and her ability brought her to MC.