To those complaining about princess using the "hostage card"
Unfortunately for you guys, "hostage" is correct. Maybe its to gather sympathy or maybe its said because it is just facts. Like others may have already said, it is usually a 'sign of goodwill' or a 'sign of peace'.
It is usually when "two countries" don't want war and one country needs to offer something as collateral (to ensure peace).
Basically, Country A puts important person A into Country B to declare "we have no intentions of declaring war so please just leave us alone (or other requests)." That way, important person A would be in danger when Country A steps out of line.
That being said, it is also a two way thing. Country B has to treat their hostages well or face political backlash/war etc.
Lets take Three Kingdoms as an example. Liu Shan went to Luoyang after surrendering. He was treated well enough to the extent he said he was "too joyful to think of home" when asked if he missed Shu. However, for all intents and purposes, he is a hostage. (and the question itself was most likely to test whether Liu Shan was still a threat. Had he replied that he missed Shu, he would most likely be killed.)
[On the other hand, I feel that Elenora is a bitch looking to usurp power based on the way she interacts with Alejandro. Its probably why she "treated him well" and then ditched him for another man. Basically its about who has more power]