Put Her to Work. Executing her for something she didn't succeed at is more than a little harsh. Imprisoning her removes a valuable
slave worker from the workforce.
Next Week. Duh, magical girl of course. I agree it's barely worth a vote. The question isn't *if* we go Willful & start training Lumen like mad, but at what priority? Magic isn't the only skill we need to survive.
Spoilering in case it's too early to talk about this.
Follow the lesson of "The Sorceror's Apprentice". Concentrate on Sense Magic first, then Resist Magic, getting Wield just high enough to take the other two over the cap for now. We need to be able to find and resist those forces before we try and weild them.