Who is Carmen from Bel Canto: A Novel and what is their importance?

Carmen is one of the terrorists that take over the Vice President's house. She is described as a smart, sharp girl, who is eager to learn. She falls in love with Gen after their training begins, and she is renown for her shyness, which gives her an uncanny ability for being able to move about unnoticed.

In the end, Gen can't save Carmen, because irregardless of their relationship, she is a terrorist, and when the government army srrives..... they've come to shoot every one of them.