A war with the mermaids was the last thing her people needed, which was why Princess Sophia didn't resist when the mermaid queen, Adria, attacked her ship and took her captive.
They needed to find a way to stop the brewing conflict between them, and going with the female might allow her to convince her to do that. She didn't expect to find herself as drawn to the mermaid as she did or for the other female to have a reason for it all.