I feel your pain re frustration at losing things. I have 4 dc and the 1st 3, all boys, all have AD(H)D and all extremely forgetful and forever losing things to varying degrees. It has cost me a fortune, e.g. with essential items like coats, gloves that HAVE to be replaced. But dh is just as bad, he lost his kindle in fact 3 times, twice he got it back, 3rd time he didn't. In the end I replaced it cos he kept 'borrowing' mine. (Now ds1 keeps 'borrowing' it so I still never have it, sigh.
Anyway, the point is, while she does need to learn the value of things, and improve her responsibility and organisation, punishing her ime is not the way to go.
As others have said, an adult wouldn't get punished for this.
If you lost your kindle, would you expect dh to ban you from watching tele for a week or something? How would you feel if your dh shouted at you for losing it?
Her punishment is the loss of the Kindle.
The way forward imo is to help her improve her organisation skills, esp as you say she is 'airy fairy' about lots of things. It is a genuine problem for her. WHat have you done so far tol help her deal with this problem? (If she had trouble with maths, you might arrange extra support, same with reading) why not with this?
I wrote mine a check list of things they have to remember to take, and went through it with them several times, till it became second nature. When they come back I try to remember to ask them if they have XY or Z with them, so I can look /send them back straight away if they've forgotten something.
HTH