It's literally in her characterization, from the way she protected her sister to the way she protected Rue in the games. She was never written in a way that implies she wouldn't want to have kids outside of the fact that the hunger games existed.
Now I'm not discrediting La Demi AT ALL, but why does she keep mentioning Denzel's height and build???? And no witness accounts despite the assault happening in public. Thats a little odd to me...