My mom found two of these in her work kitchen. Do you know what they are?

I've seen those half-circle pots, but typically they have handles. Also, the item pictured here appears to be made of aluminum and does not show wear consistent with a WWII-era kitchen utensil (especially since aluminum is so soft).

Here is a half-circle pot at eBay:

https://www.ebay.com/itm/Vintage-MIRRO-Aluminum-Half-Circle-Pots-w-Lids-Set-of-2-Prepper-/181631453464

one that shows wear more consistent with something that is 50, 60, 70+ years old.

Moreover, the item photographed above does not have a handle suitable for stovetop use but a pair of wire lifting handles, more evidence that it was designed to be submerged in another vessel.

Thanks!

Like for canning?

Ah! I understand what you're saying!

I think you have it- the double handles would certainly make sense for that.

Not so sure about the canning thing. Normally you can in the storage container (like a mason jar). Sticking the mason jar in this bain marie might be a little awkward when you need to pull it out.

I was under the impression that a more common canning device was a wire rack, letting the hot water flow out when you remove the holder from the water.

This device seems more appropriate for holding a sauce, custard, whatever during a restaurant service, not as a carrier to hold other recipient containers.

At least that's the way I would use it.