That's excellent information, thanks.

Her initial impression was that the circuit in question was a 110 because she plugged a space heater into a regular wall outlet and caused the circuit to trip that way. However, this doesn't rule out that the circuit might have gone to a sub panel she's not seeing, or, was wired in a poor fashion where it SHOULD have gone to a sub panel and didn't.

But this information is great to go on so that we can investigate more. Thanks!