However it's important that you should see your GP as soon as possible in order that he/she can rule out other possibilities, such as the early signs of Parkinson's Disease. (NB: Don't start panicking when you read that. It's probably VERY unlikely that you've got anything seriously wrong with you but, if you have, then early treatment will result in the best outcome. The sooner you see your GP, the sooner you can stop worrying about it).
Do you mean twitching (like a momentary muscular spasm) or do you mean tremor, as In Chris' link, which to me is a continual shaking of varying degree. That could make a difference. If you're worried I'd see a GP and stay off looking it up on the internet. That's enough to make anyone twitch.
Parkinson's is very unlikely anyway but, as you say PF, it's even more unlikely in a young person. (I'd not clicked on Daisy's profile to read her previous posts)
Here is a 14year old girl? been on AB for just over a week and in that time she has complained of "invisible friends"..." not sure of her sexuality" and now "twitching"
Any ideas? My diagnosis will result in my post being removed.
If your diagnosis is that the questioner is a troll, Sqad, then I will admit that it was a possibility that crossed my mind too.
However I've also taught teenagers and encountered plenty of them who've had all sorts of problems, often simultaneously, so I'd prefer to give the questioner the benefit of any doubt here.