Lots of 2-player game suggestions in Good two-player games (some of which are language-independent).
Hive, Jaipur, and Patchwork are go-tos for me at 2p, language-independent, and easy to learn and play.
Caesar! Seize Rome in 20 Minutes! could work if the theme is ok, although might be complicated depending on the kid’s actual age (“less than 13” covers a pretty enormous range of cognitive capabilities).