and she traded her newspaper for the support.

I offered her my arm with careful exaggeration, and she traded her newspaper for the support. It was strange, I reflected, as we went out into the golden evening of the Byzantine streets, that even in the weirdest circumstances, the most troubling episodes of one’s life, the greatest divides from home and familiarity, there were these moments of undeniable joy.”

Please tell what's this sentence mean "and she traded her newspaper for the support."

(She was reading the newspaper when he met her.)

Thanks