Here are some packed lunch ideas. https://www.dietdoctor.com/low-carb/recipes/lunch
Also check the website DitchtheCarbs, the pharmacist who runs it has kids with allergies, she has many attractive lunchbox ideas to keep lunch fun and healthy. If the microwave last night's extra food (made purposely for next lunch) doesn't appeal, these are more finger foods enjoyed by adults and kids alike here. https://www.ditchthecarbs.com/low-carb-kids/