Leak-proof small insulated milk container recommendation for my daughter’s lunches to save money?

[u/Pretend-Read8385]

I keep wasting money on individual milk and juice boxes because every container I’ve tried leaks and ends up making a mess in her backpack and ruining her papers from school.

School lunch is free, except she is picky and won’t eat it and you can only get milk if you take the whole lunch. It’s ridiculous, but it is what it is.

Ideally, I’d like one container with milk for lunch and another for juice with her snack.

She’s 10 and cool now, so no rainbows or unicorns.

Links would be appreciated. TIA

[u/cole_panchini]

I used the Rubbermaid litterless 250mL juice box for milk, it didn’t spill. However this was many years ago and it may have changed in quality. Another option that I have used for school milk is a small mason jar, seals great.