Rue knows she will not win. She knows that, if she's lucky, it'll be quick without too much pain, but she still remembers that one terrifying year where half the contenders were killed by a horde of wasps, giant things that had been manipulated somewhere in the Capital. The screams were terrible, and her mother had covered her eyes as the scene unfolded, brutal in that way the Capital loved to define itself by. She shivers just before they test her, remembering, and hopes that the worst thing she'll deal with is starvation.
It won't be, but that's one thing she'd know how to survive.
She lets herself slip up, though, once she meets Katniss, and that's why it all ends, isn't it? It's nice, to have someone, even if the girl from District 12 is cold and suspicious. There's something comforting about a partner, even if the ones that are watching hope to see both fail. And they get to see at least one: a spear, the blade sharp in the soft flesh of her body. Rue can appreciate the injustice of it, youth and pain of it all. But Katniss sings to her, Katniss loves her—it doesn't matter that they both knew neither could both live, doesn't matter that Rue is glad to have it end this way. It's worth it, and she just needs Katniss to make it so.