I'm very sorry to hear about your loss, Thomas.
If you were feeding every day it's not going to have been a starvation issue. The clones are very tolerant of fasting and will be fine for a week or two without anything to eat.
Since you haven't mentioned anything, I'm assuming she was fine until she suddenly and unexpectedly died.
The jaw certainly does seem to indicate a problem. With a jaw like that I imagine she'd have trouble feeding. She does look skinny, and if she was getting enough food this possibly indicates that she was kept very dry, although they're very tolerant of dry conditions. Were you spraying her enclosure? How often? (This is unlikely to be the issue, especially given that jaw, but it's good to rule things out).
The jaw really does seem unusual, and I'd be guessing that it's either a physical injury (was the enclosure open-topped? Could a mouse or something have got in?) or a calcium deficiency as others have guessed. They don't seem to need a heck of a lot of calcium and I suspect you'd get away with only dusting one in every five or ten meals (although I dust every meal and recommend everyone does the same, just for good measure). I very much doubt the strange jaw is unrelated to the death. When geckoes die of any health issue it's common for it to happen during sloughing. The sloughing process is a bit of a challenge and requires a bit of energy expenditure. Normally it isn't an issue, but if the lizard is slowly getting to the point of death, the slough is likely to be the time it'll happen, so the slough likely wasn't related to the death. Your lizard certainly doesn't seem to have had a bad enough slough for it to be a significant problem.
If you've been giving her calcium supplements and she had been feeding up until she died, I really can't help but lean towards suspecting a mechanical injury from some source. I've seen a small number of geckoes with calcium deficiencies, and to have such a severe jaw issue with no other problems seems unlike what I'm familiar with. I've never seen calcium deficiency in a Clone Gecko, so what I've seen may not be relevant, but the problems have been in the legs. I've seen a lot of calcium issues in dragons (including one I raised myself many years ago - the only calcium-related issue I've ever personally had with reptile) and often these include jaw issues, but I haven't seen anything like yours. It looks mechanical.
I've sold out of clones for the season, but get in touch around November and we'll see what we can work out.
