I only saw the edit about this being a waste of time later on. Well, in general playing games is a waste of time, that's the point. There's no need to be rude about someone asking questions. I have a backup of the save for research purposes. Just because this dwarf, not a real person, just an abstraction represented by interaction between a computer program and the player, went insane, doesn't mean I haven't learned anything. I thanked you for the substantive reply previously, and the information there was still useful, in a general sense. It didn't seem like that was the issue in this particular case, but knowing that you need to use candy cloth if you have it is helpful, for example. I am not an expert at this game, but neither a total noob, so I had tried a lot of things and looked up or already knew a lot of information, but some of what you posted was either new to me or finally stood out to me in a way that made sense, so it was helpful. Questions are asked to learn, not just to succeed in the moment. I don't really care that much that a single dwarf in a virtual world went insane, I care more that I know why the mechanics of the game were working as they were.
I can still load up that save to figure it out, but I have already exhausted all ideas so far to try to do it for "Science!!" etc. By all accounts, including the extra info you provided, I have everything in place that the dwarf should need. I have no further ideas to try without additional input, since I absolutely have many logs, many cloth of all base types, many leather, at least 4 or 5 of every major category of block (stone, wood, metal, clay, glass), and many bones, all easily accessible with no active burrow (and not blocked by tasks, I triple-checked and set up stockpiles dedicated to the purpose). Your input was welcome, and I don't have any candy and the dwarf has no relevant preferences (unless copper is relevant?). I just have no copper with which to test... well, I have some copper now, as goblinite but there was absolutely no way to get it before she went crazy.
Is it possible she wanted copper blocks specifically? I'm actually curious about that mechanic for future reference.