Responses

Ibelin is secretly a bitch. She is an attention seeking trash who wants all the fishes (and maybe even all men) in a harem because "I am so beautiful that I deserved everyone's affection" She is rottenly spoiled and would gladly get rid of Latte (because she thinks Latte is stealing her men) The prince is bad character too! (he would literally f*ck any woman that grabs his attention) So, she deserved that ending.
Spoilers (not sure how accurate these are I could be wrong I read them months ago)
Latte and Arwin end up together
I think Kenneth/Kevin/ whatever his name is eventually realises that Ibelin is plain and boring (like Arwin did, hence he left the fishery) and finds a nice girl to marry
Ibelin ends up becoming one of the prince's concubines but after a small while the prince realises how boring she is and never visits her