It’s a Toyota hybrid though, they are regularly used for camping.

www.reddit.com/r/priusdwellers/

The engine getting overheated isn’t usually a concern because it only turns on to charge the big battery. Sometimes if it’s hot inside the car, the engine in Toyota hybrids will stay on indefinitely, but thats to reduce the heat on the big battery. If the inside of the car is cool, then the big battery is cooled and the engine won’t stay on.

I would never use this info as an excuse to do what she did though ofc, no one should leave children that small unattended in a car, not even for 5minutes.