I have only seen the series and not read any of the books.
Tyrion marries off Cersei's daughter, Myrcella Baratheon into the Dorne family.
Later Oberyn Martell arrives planning revenge against the Lannisters.
Oberyn and Cersei talk in front of a boat. She says it is a gift for her daughter but you get the feeling it is a bribe to him for her daughter's safety.
Oberyn states that they do not make slaves of princesses in Dorne and Cersei counters that they do not rape princesses in King's Landing; a statement we are lead to believe is false.
This scene implies that Myrcella is not living the privileged life of a princess in Dorne, but in fact has had a rather terrible life.
Even in the Game of Thrones' dark and bloody world, I thought that children would be safe from the scheming.
Do we ever find out more details of Myrcella's fate ?