The reason the tablets exploded was because of trapped moisture in the clay. People tend to think it’s air bubbles that are the main culprit, but it is really the expansion of the water into steam trying to escape. These explosions can largely be avoided by making sure the clay completely dries to greenware (bone dry) before firing it. If she had an electric kiln she could even fire it under 200F for 18 hours before ramping up to bisque (first firing) the tablets, but obviously this ain’t a thing in this world!
There’s no way Maïn could have known this unless she was really into ceramics and pottery. I’m a ceramicist so I expected that to happen. Not nearly enough drying time!! Poor thing.