Theris simply won't let you use her raw materials if she thinks you're going to craft something nobody needs right now. Otherwise, she'll allow you to use her metal and firewood. She has 105 iron ingots, so 105 pounds of already-smelted iron that's ready for forging into items. Forging steel objects will require more time, but I think Theris has all she needs to make steel, it'll just take some time to make it without any existing coal, coke, charcoal, or the like in her initial raw materials.
Roleplay with Theris if you want to use her raw materials for anything. She doesn't mind letting anyone use her portable forge, anvil, bellows, tongs, hammer, fuller, and other tools, and they're masterwork, so that'll add +2 to any Craft checks to forge items with Theris' tools.