>>33334818if there's ever an occasion to throw in what country they or their parents are from, do so. if there's ever an occasion for them to break out of english and rattle off some moon, do so in a way the reader will understand. should the situation allow this kind of explication, address your character's cheekbones, lips, teeth, hair quality, whether they are lightskinned or darkskinned for their ethnicity, etc. i also wouldn't have a problem with just saying they have "small eyes" since that's not strictly an asian thing, and there are tons of asians with comparatively "big eyes" but that's just me.
pic related, huge eyes