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/Subject-Ad-5249]

Whatever you get you can put it into a large gallon sized ziplock style baggie for extra protection. I'm 45 and have large ziplock baggies I've reused for years to avert and contain disasters.