2010s Fantasy Book
I don't remember so much but I do know the main character was a gir; and a group of 5 people- 2 girls and 3 boys
One of the girls is a young princess (~10 yrs) from this kingdom (I THINK her name started with an i). The group went to visit that kingdom, and it was attacked (not by them) and possibly destroyed- the young princess escaped with the group
One guy in the group was a sailor i think (maybe a prince tho) and the young princess didn't trust/like him. I remember one scene they were looking for something in a library and the girl went to a secret room or something and found a scroll
the 2 other guys and the main woman were in a love triangle
There was a mission the group had- i don't exactly know what it was- but they were going to different kingdoms (trying to get support for something maybe)
There was also a scene on a ship though i dont really remember it so much
The cover of the book was blue, the picture might be an ocean with a castle on an island (but a big, tall castle)
the title was something like "__ of __" but it might not be.
The book is not Throne of Glass
It MIGHT be Crown of Bones??? Theres a chance i accidently read the second book first, cause i dont remember the main woman having parents and i don't think theres a Piper (but maybe im wrong)
please help!!