Yes. In the beginning, their love was not all real. In order to stay in the favor of the audience, they pretended to be "star-crossed lovers." She does mention in the cave scene that she feels a "hunger" in her body while she kissed him. Peeta was always in love with Katniss, but it took her a while to truly be in love. I think she wouldn't let herself fall in love because the people she loved had died or become hurt because of her. But in the end, yes. They put their lives on the line for each other, and I think love is the reason they did so.