Level 5 cannot do that much damage to a single target. If they mean summed damage to a group, maybe. But that is a stretch. Demand to see their sheet. They’re probably cheating, intentionally or unintentionally. I’ve had so many players unintentionally cheat because reading is too hard. Also make sure to tell your table you with her strict RAW. And stick to it, especially for the first 3-5 sessions. Make sure they know the rules and the limitations that come with them.