i agree with flux and disagree with those advocating the lower temperatures. i always provided basking spots of around 90 for all of my clutches. at that age at least.
neonates are the only ones that got more mild temperatures.
seems to me like you could even potentially stunt or slow growth by limiting their metabolic rate. sure they eat less when theyre cool but theyre going to grow more slowly. the only reason i see doing that, is as was mentioned, is to limit egg production in females pre-ovulation if you dont intend on breeding.
i do understand the concern with over heating or burns but honestly ive nver had a chameleon incapable of walking away from the light of its own accord, and the only reason i could see it being detrimental is if you arent hydrating your chameleons enough or if your temperature readings are inaccurate and actually way too high (100F+)
feels to me like a basking temperature of 80 is playing it a bit too safe for a growing girl. but at the same time i only have my own experience as a frame of reference on the matter and as there are others advocating and conducting the practice one could assume its a perfectly safe method.
as angie said she may or may not like the mist. sparying indirectly is the best approach. if she wants to she will probably walk into it to lap up the water droplets. youll find out whether or not she wants to be sprayed directly by how she reacts.
and i recommend the pressure sprayer dave was talking about. its not that trigger sprayers arent effective but people tend to get lazy and wont squirt a sufficient amount for a long enough. it will actually take some chams upwards of 10 min + to even get interested in the water. with the pressure sprayer youll have a hydrated cham and happy forearms. depending on the sparyer you get you can even just pump it up, position it, and lock it on. so you dont have to wait around. and that way youll be more prone to give her extra water on the fly.
as far as supplementing her diet with veggies its all up to her what she will eat. ive had them eat bananas grapes and oranges (even though citrus isnt a great idea) only ever had 3 chams that would do this (one of which i tricked) and never on a regular basis. and 3 is very few considering how many ive had over the years.
veileds in particular will eat the plants you have in your cage but not very often. hence why you need to check out safe plant lists.
you can try hand feeding greens but i dont see vegetation being appealing enough. pretty much anything on sandras wet gutload list is a good idea. whether or not she will want to eat it is a totally different story.
and as far as regulating the temperature is concerned all you have to do is raise or lower the basking spot accordingly. some people will say move the light becuase of the potential for burns if the cham were to climb the screen and hang from the ceiling under the light. this is an actual serious concern if you have a wall crawler but i still find the best approch is to furnish the cage heavily, if shes doing that, to dissuade her from crawling right up to the light. and even so they should be able to realize its way too hot right under the light. i saw this happen with a juvie panther once. walked under the light and immediately dropped from the ceiling. lol never saw him do that again.
anyways goodluck. youll find lots of contradictory perspectives on chameleons keeping. dosnt mean anyone is right or wrong (though sometimes people are very wrong) it just means theres more than one way to skin a cat. just do a lot of research and find a balance that works best for you. and experiment. if people dont experiment we dont learn anything as a community (but dont go microwaving your chameleon)